Antique.CoulombTwoBodyType

CoulombTwoBody(z₁=-1, z₂=1, m₁=1.0, m₂=1.0, mₑ=1.0, a₀=1.0, Eₕ=1.0, ℏ=1.0)

$z₁$ is the charge number of particle 1, $z₁$ is the charge number of particle 2, $m₁$ is the mass of particle 1, $m₂$ is the mass of particle 2, $m_\mathrm{e}$ is the electron mass (use the same unit as $m₁$ and $m₂$. For example of hydrogen atom, use $m_\mathrm{e}=9.1093837139\times10^{-31}\mathrm{kg}$, $m_1=9.1093837139\times10^{-31}\mathrm{kg}$ and $m_2=1.67262192595\times10^{-27}\mathrm{kg}$ in the IS unit system, use $~m_\mathrm{e}=1.0~m_\mathrm{e}$, $m_1=1.0~m_\mathrm{e}$ and $m_2=1836.152673426~m_\mathrm{e}$ in the atomic unit.), $a_0$ is the Bohr radius, $E_\mathrm{h}$ is the Hartree energy and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.DeltaPotentialType

DeltaPotential(α=1.0, m=1.0, ℏ=1.0)

$\alpha$ is the potential strength, $m$ is the mass of particle and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.HarmonicOscillatorType

HarmonicOscillator(k=1.0, m=1.0, ℏ=1.0)

$k$ is the force constant, $m$ is the mass of particle and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.HydrogenAtomType

HydrogenAtom(Z=1, mₑ=1.0, a₀=1.0, Eₕ=1.0, ℏ=1.0)

$Z$ is the atomic number, $m_\mathrm{e}$ is the electron mass, $a_0$is the Bohr radius, $E_\mathrm{h}$ is the Hartree energy and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.InfinitePotentialWellType

InfinitePotentialWell(L=1.0, m=1.0, ℏ=1.0)

$L$ is the length of the box, $m$ is the mass of particle and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.InfinitePotentialWell3DType

InfinitePotentialWell3D(Lx=1.0, Ly=1.0, Lz=1.0, m=1.0, ℏ=1.0)

$L_x,L_y,L_z$ are the lengths of the box in $x$,$y$,$z$-direction, $m$ is the mass of particle and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.MorsePotentialType

MP = MorsePotential(rₑ=2.0, Dₑ=0.1, k=0.1, µ=918.1, ℏ=1.0)

$r_\mathrm{e}$ is the equilibrium bond distance, $D_\mathrm{e}$ is the the well depth , $k$ is the force constant, $\mu$ is the reduced mass and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.PoschlTellerType

PoschlTeller(λ=1.0, m=1.0, ℏ=1.0, x₀=1.0)

$\lambda$ determines the potential strength. Currently only integer values for $\lambda$ are supported.

Antique.RigidRotorType

RigidRotor(m₁=1.0, m₂=1.0, R=1.0, ℏ=1.0)

$m₁$ and $m₂$ are mass of two particles, $R$ is the distance, and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.SphericalOscillatorType

SphericalOscillator(k=1.0, μ=1.0, ℏ=1.0)

$k$ is the force constant, $μ$ is the mass of particle and $\hbar$ is the reduced Planck constant (Dirac's constant).

Antique.EMethod

E(model::CoulombTwoBody; n=1)

\[E_n = -\frac{(z_1 z_2)^2}{2n^2} \frac{\mu}{m_\mathrm{e}} E_\mathrm{h},\]

where $\mu=\left(\frac{1}{m_1}+\frac{1}{m_2}\right)^{-1}$ is the reduced mass of particle 1 and particle 2, $E_\mathrm{h}$ is the Hartree energy, one of atomic unit. About atomic units, see section 3.9.2 of the IUPAC GreenBook. In other units, $E_\mathrm{h} = 27.211~386~245~988(53)~\mathrm{eV}$ from here.

Antique.EMethod

E(model::DeltaPotential)

\[E = - \frac{m\alpha^2}{2\hbar^2}\]

Antique.EMethod

E(model::HarmonicOscillator; n=0)

\[E_n = \hbar \omega \left( n + \frac{1}{2} \right),\]

where $\omega = \sqrt{k/m}$ is the angular frequency.

Antique.EMethod

E(model::HydrogenAtom; n=1)

\[E_n = -\frac{m_\mathrm{e} e^4 Z^2}{2n^2(4\pi\varepsilon_0)^2\hbar^2} = -\frac{Z^2}{2n^2} E_\mathrm{h},\]

where $E_\mathrm{h}$ is the Hartree energy, one of atomic unit. About atomic units, see section 3.9.2 of the IUPAC GreenBook. In other units, $E_\mathrm{h} = 27.211~386~245~988(53)~\mathrm{eV}$ from here.

Antique.EMethod

E(model::InfinitePotentialWell3D; nx=1, ny=1, nz=1)

\[E_{n_x,n_y,n_z} = \frac{\hbar^2 \pi^2}{2 m} \left(\frac{n_x^2}{L_x^2} + \frac{n_y^2}{L_y^2} + \frac{n_z^2}{L_z^2}\right)\]

Antique.EMethod

E(model::InfinitePotentialWell; n=1)

\[E_n = \frac{\hbar^2 n^2 \pi^2}{2 m L^2}\]

Antique.EMethod

E(model::MorsePotential; n=0)

\[E_n = - D_\mathrm{e} + \hbar \omega \left( n + \frac{1}{2} \right) - \chi \hbar \omega \left( n + \frac{1}{2} \right)^2,\]

where $\omega = \sqrt{k/µ}$ and $\chi = \frac{\hbar\omega}{4D_\mathrm{e}}$ are defined.

Antique.EMethod

E(model::PoschlTeller; n=0)

\[E_n = -\frac{\hbar^2}{m x_0^2}\frac{\mu^2}{2},\]

where $\mu = \mu(n) = n_\mathrm{max}-n+1$, and $n_\mathrm{max} = \left\lfloor \lambda \right\rfloor - 1$.

Antique.EMethod

E(model::RigidRotor; l=0)

\[E_l = \frac{\hbar^2}{2I}l(l+1),\]

where $I=\mu R^2$ is the moment of inertia, $R$ is the distance, and $\mu$ is the reduced mass of the two particles.

Antique.EMethod

E(model::SphericalOscillator; n=0, l=0)

\[E_{nl} = \left(2n + l + \frac{3}{2}\right)\hbar \omega,\]

where $\omega = \sqrt{k/\mu}$.

Antique.HMethod

H(model::HarmonicOscillator, x; n=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} H_{n}(x) &:= (-1)^n \mathrm{e}^{x^2} \frac{\mathrm{d}^n}{\mathrm{d}x^n} \mathrm{e}^{-x^2} \\ &= n! \sum_{m=0}^{\lfloor n/2 \rfloor} \frac{(-1)^m}{m! (n-2m)!}(2 x)^{n-2m}. \end{aligned}\]

Examples:

\[\begin{aligned} H_{0}(x) &= 1, \\ H_{1}(x) &= 2 x, \\ H_{2}(x) &= -2 + 4 x^{2}, \\ H_{3}(x) &= -12 x + 8 x^{3}, \\ H_{4}(x) &= 12 - 48 x^{2} + 16 x^{4}, \\ H_{5}(x) &= 120 x - 160 x^{3} + 32 x^{5}, \\ H_{6}(x) &= -120 + 720 x^{2} - 480 x^{4} + 64 x^{6}, \\ H_{7}(x) &= -1680 x + 3360 x^{3} - 1344 x^{5} + 128 x^{7}, \\ H_{8}(x) &= 1680 - 13440 x^{2} + 13440 x^{4} - 3584 x^{6} + 256 x^{8}, \\ H_{9}(x) &= 30240 x - 80640 x^{3} + 48384 x^{5} - 9216 x^{7} + 512 x^{9}, \\ &\vdots \end{aligned}\]

Antique.LMethod

L(model::CoulombTwoBody, x; n=0, k=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} L_n^{k}(x) &= \frac{\mathrm{d}^k}{\mathrm{d}x^k} L_n(x) \\ &= \frac{\mathrm{d}^k}{\mathrm{d}x^k} \frac{1}{n!} \mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right) \\ &= \sum_{m=0}^{n-k} (-1)^{m+k} \frac{n!}{m!(m+k)!(n-m-k)!} x^m \\ &= (-1)^k L_{n-k}^{(k)}(x), \end{aligned}\]

where Laguerre polynomials are defined as $L_n(x)=\frac{1}{n!}\mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right)$.

Examples:

\[\begin{aligned} L_0^0(x) &= 1, \\ L_1^0(x) &= 1 - x, \\ L_1^1(x) &= 1, \\ L_2^0(x) &= 1 - 2 x + 1/2 x^2, \\ L_2^1(x) &= 2 - x, \\ L_2^2(x) &= 1, \\ L_3^0(x) &= 1 - 3 x + 3/2 x^2 - 1/6 x^3, \\ L_3^1(x) &= 3 - 3 x + 1/2 x^2, \\ L_3^2(x) &= 3 - x, \\ L_3^3(x) &= 1, \\ L_4^0(x) &= 1 - 4 x + 3 x^2 - 2/3 x^3 + 5/12 x^4, \\ L_4^1(x) &= 4 - 6 x + 2 x^2 - 1/6 x^3, \\ L_4^2(x) &= 6 - 4 x + 1/2 x^2, \\ L_4^3(x) &= 4 - x, \\ L_4^4(x) &= 1, \\ \vdots \end{aligned}\]

Antique.LMethod

L(model::HydrogenAtom, x; n=0, k=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} L_n^{k}(x) &= \frac{\mathrm{d}^k}{\mathrm{d}x^k} L_n(x) \\ &= \frac{\mathrm{d}^k}{\mathrm{d}x^k} \frac{1}{n!} \mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right) \\ &= \sum_{m=0}^{n-k} (-1)^{m+k} \frac{n!}{m!(m+k)!(n-m-k)!} x^m \\ &= (-1)^k L_{n-k}^{(k)}(x), \end{aligned}\]

where Laguerre polynomials are defined as $L_n(x)=\frac{1}{n!}\mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right)$.

Examples:

\[\begin{aligned} L_0^0(x) &= 1, \\ L_1^0(x) &= 1 - x, \\ L_1^1(x) &= 1, \\ L_2^0(x) &= 1 - 2 x + 1/2 x^2, \\ L_2^1(x) &= 2 - x, \\ L_2^2(x) &= 1, \\ L_3^0(x) &= 1 - 3 x + 3/2 x^2 - 1/6 x^3, \\ L_3^1(x) &= 3 - 3 x + 1/2 x^2, \\ L_3^2(x) &= 3 - x, \\ L_3^3(x) &= 1, \\ L_4^0(x) &= 1 - 4 x + 3 x^2 - 2/3 x^3 + 5/12 x^4, \\ L_4^1(x) &= 4 - 6 x + 2 x^2 - 1/6 x^3, \\ L_4^2(x) &= 6 - 4 x + 1/2 x^2, \\ L_4^3(x) &= 4 - x, \\ L_4^4(x) &= 1, \\ \vdots \end{aligned}\]

Antique.LMethod

L(model::MorsePotential, x; n=0, α=0)

Note

The generalized Laguerre polynomials $L_n^{(\alpha)}(x)$, not the associated Laguerre polynomials $L_n^{k}(x)$, are used in this model.

Rodrigues' formula & closed-form:

\[\begin{aligned} L_n^{(\alpha)}(x) &= \frac{x^{-\alpha}e^x}{n!} \frac{d^n}{dx^n}\left(x^{n+\alpha}e^{-x}\right) \\ &= \sum_{k=0}^n(-1)^k \left(\begin{array}{l} n+\alpha \\ n-k \end{array}\right) \frac{x^k}{k !} \\ &= \sum_{k=0}^n(-1)^k \frac{\Gamma(\alpha+n+1)}{\Gamma(\alpha+k+1)\Gamma(n-k+1)} \frac{x^k}{k !}. \end{aligned}\]

Examples:

\[\begin{aligned} L_0^{(0)}(x) &= 1, \\ L_1^{(0)}(x) &= 1 - x, \\ L_1^{(1)}(x) &= 2 - x, \\ L_2^{(0)}(x) &= 1 - 2 x + 1/2 x^{2}, \\ L_2^{(1)}(x) &= 3 - 3 x + 1/2 x^{2}, \\ L_2^{(2)}(x) &= 6 - 4 x + 1/2 x^{2}, \\ L_3^{(0)}(x) &= 1 - 3 x + 3/2 x^{2} - 1/6 x^{3}, \\ L_3^{(1)}(x) &= 4 - 6 x + 2 x^{2} - 1/6 x^{3}, \\ L_3^{(2)}(x) &= 10 - 10 x + 5/2 x^{2} - 1/6 x^{3}, \\ L_3^{(3)}(x) &= 20 - 15 x + 3 x^{2} - 1/6 x^{3}, \\ L_4^{(0)}(x) &= 1 - 4 x + 3 x^{2} - 2/3 x^{3} + 1/24 x^{4}, \\ L_4^{(1)}(x) &= 5 - 10 x + 5 x^{2} - 5/6 x^{3} + 1/24 x^{4}, \\ L_4^{(2)}(x) &= 15 - 20 x + 15/2 x^{2} - 1 x^{3} + 1/24 x^{4}, \\ L_4^{(3)}(x) &= 35 - 35 x + 21/2 x^{2} - 7/6 x^{3} + 1/24 x^{4}, \\ L_4^{(4)}(x) &= 70 - 56 x + 14 x^{2} - 4/3 x^{3} + 1/24 x^{4}, \\ \vdots \end{aligned}\]

Antique.LMethod

L(model::SphericalOscillator, x; n=0, α=0)

Note

The generalized Laguerre polynomials $L_n^{(\alpha)}(x)$, not the associated Laguerre polynomials $L_n^{k}(x)$, are used in this model.

Rodrigues' formula & closed-form:

\[\begin{aligned} L_n^{(\alpha)}(x) &= \frac{x^{-\alpha}e^x}{n!} \frac{d^n}{dx^n}\left(x^{n+\alpha}e^{-x}\right) \\ &= \sum_{k=0}^n(-1)^k \left(\begin{array}{l} n+\alpha \\ n-k \end{array}\right) \frac{x^k}{k !} \\ &= \sum_{k=0}^n(-1)^k \frac{\Gamma(\alpha+n+1)}{\Gamma(\alpha+k+1)\Gamma(n-k+1)} \frac{x^k}{k !}. \end{aligned}\]

Examples:

\[\begin{aligned} L_0^{(0)}(x) &= 1, \\ L_1^{(0)}(x) &= 1 - x, \\ L_1^{(1)}(x) &= 2 - x, \\ L_2^{(0)}(x) &= 1 - 2 x + 1/2 x^{2}, \\ L_2^{(1)}(x) &= 3 - 3 x + 1/2 x^{2}, \\ L_2^{(2)}(x) &= 6 - 4 x + 1/2 x^{2}, \\ L_3^{(0)}(x) &= 1 - 3 x + 3/2 x^{2} - 1/6 x^{3}, \\ L_3^{(1)}(x) &= 4 - 6 x + 2 x^{2} - 1/6 x^{3}, \\ L_3^{(2)}(x) &= 10 - 10 x + 5/2 x^{2} - 1/6 x^{3}, \\ L_3^{(3)}(x) &= 20 - 15 x + 3 x^{2} - 1/6 x^{3}, \\ L_4^{(0)}(x) &= 1 - 4 x + 3 x^{2} - 2/3 x^{3} + 1/24 x^{4}, \\ L_4^{(1)}(x) &= 5 - 10 x + 5 x^{2} - 5/6 x^{3} + 1/24 x^{4}, \\ L_4^{(2)}(x) &= 15 - 20 x + 15/2 x^{2} - 1 x^{3} + 1/24 x^{4}, \\ L_4^{(3)}(x) &= 35 - 35 x + 21/2 x^{2} - 7/6 x^{3} + 1/24 x^{4}, \\ L_4^{(4)}(x) &= 70 - 56 x + 14 x^{2} - 4/3 x^{3} + 1/24 x^{4}, \\ \vdots \end{aligned}\]

Antique.PMethod

P(model::CoulombTwoBody, x; n=0, m=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} P_n^m(x) &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} P_n(x) \\ &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right] \\ &= \frac{1}{2^n} (1-x^2)^{m/2} \sum_{j=0}^{\left\lfloor\frac{n-m}{2}\right\rfloor} (-1)^j \frac{(2n-2j)!}{j! (n-j)! (n-2j-m)!} x^{(n-2j-m)}. \end{aligned},\]

where Legendre polynomials are defined as $P_n(x) = \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right]$. Note that $P_l^{-m} = (-1)^m \frac{(l-m)!}{(l+m)!} P_l^m$ for $m<0$. (It is not compatible with $P_k^m(t) = (-1)^m\left( 1-t^2 \right)^{m/2} \frac{\mathrm{d}^m P_k(t)}{\mathrm{d}t^m}$ caused by $(-1)^m$.) The specific formulae are given below.

Examples:

\[\begin{aligned} P_{0}^{0}(x) &= 1, \\ P_{1}^{0}(x) &= x, \\ P_{1}^{1}(x) &= \left(+1\right)\sqrt{1-x^2}, \\ P_{2}^{0}(x) &= -1/2 + 3/2 x^{2}, \\ P_{2}^{1}(x) &= \left(-3 x\right)\sqrt{1-x^2}, \\ P_{2}^{2}(x) &= 3 - 6 x, \\ P_{3}^{0}(x) &= -3/2 x + 5/2 x^{3}, \\ P_{3}^{1}(x) &= \left(3/2 - 15/2 x^{2}\right)\sqrt{1-x^2}, \\ P_{3}^{2}(x) &= 15 x - 30 x^{2}, \\ P_{3}^{3}(x) &= \left(15 - 30 x\right)\sqrt{1-x^2}, \\ P_{4}^{0}(x) &= 3/8 - 15/4 x^{2} + 35/8 x^{4}, \\ P_{4}^{1}(x) &= \left(- 15/2 x + 35/2 x^{3}\right)\sqrt{1-x^2}, \\ P_{4}^{2}(x) &= -15/2 + 15 x + 105/2 x^{2} - 105 x^{3}, \\ P_{4}^{3}(x) &= \left(105 x - 210 x^{2}\right)\sqrt{1-x^2}, \\ P_{4}^{4}(x) &= 105 - 420 x + 420 x^{2}, \\ & \vdots \end{aligned}\]

Antique.PMethod

P(model::HydrogenAtom, x; n=0, m=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} P_n^m(x) &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} P_n(x) \\ &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right] \\ &= \frac{1}{2^n} (1-x^2)^{m/2} \sum_{j=0}^{\left\lfloor\frac{n-m}{2}\right\rfloor} (-1)^j \frac{(2n-2j)!}{j! (n-j)! (n-2j-m)!} x^{(n-2j-m)}. \end{aligned},\]

where Legendre polynomials are defined as $P_n(x) = \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right]$. Note that $P_l^{-m} = (-1)^m \frac{(l-m)!}{(l+m)!} P_l^m$ for $m<0$. (It is not compatible with $P_k^m(t) = (-1)^m\left( 1-t^2 \right)^{m/2} \frac{\mathrm{d}^m P_k(t)}{\mathrm{d}t^m}$ caused by $(-1)^m$.) The specific formulae are given below.

Examples:

\[\begin{aligned} P_{0}^{0}(x) &= 1, \\ P_{1}^{0}(x) &= x, \\ P_{1}^{1}(x) &= \left(+1\right)\sqrt{1-x^2}, \\ P_{2}^{0}(x) &= -1/2 + 3/2 x^{2}, \\ P_{2}^{1}(x) &= \left(-3 x\right)\sqrt{1-x^2}, \\ P_{2}^{2}(x) &= 3 - 6 x, \\ P_{3}^{0}(x) &= -3/2 x + 5/2 x^{3}, \\ P_{3}^{1}(x) &= \left(3/2 - 15/2 x^{2}\right)\sqrt{1-x^2}, \\ P_{3}^{2}(x) &= 15 x - 30 x^{2}, \\ P_{3}^{3}(x) &= \left(15 - 30 x\right)\sqrt{1-x^2}, \\ P_{4}^{0}(x) &= 3/8 - 15/4 x^{2} + 35/8 x^{4}, \\ P_{4}^{1}(x) &= \left(- 15/2 x + 35/2 x^{3}\right)\sqrt{1-x^2}, \\ P_{4}^{2}(x) &= -15/2 + 15 x + 105/2 x^{2} - 105 x^{3}, \\ P_{4}^{3}(x) &= \left(105 x - 210 x^{2}\right)\sqrt{1-x^2}, \\ P_{4}^{4}(x) &= 105 - 420 x + 420 x^{2}, \\ & \vdots \end{aligned}\]

Antique.PMethod

P(model::PoschlTeller, x; n=0, m=0)

Associated Legendre polynomials are the associated Legendre functions for integer indices. Here we use the same notation of the associated Legendre functions as in the model HydrogenAtom.

\[\begin{aligned} P_n^m(x) &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} P_n(x) \\ &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right] \\ &= \frac{1}{2^n} (1-x^2)^{m/2} \sum_{j=0}^{\left\lfloor\frac{n-m}{2}\right\rfloor} (-1)^j \frac{(2n-2j)!}{j! (n-j)! (n-2j-m)!} x^{(n-2j-m)}. \end{aligned}\]

Antique.PMethod

P(model::RigidRotor, x; n=0, m=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} P_n^m(x) &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} P_n(x) \\ &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right] \\ &= \frac{1}{2^n} (1-x^2)^{m/2} \sum_{j=0}^{\left\lfloor\frac{n-m}{2}\right\rfloor} (-1)^j \frac{(2n-2j)!}{j! (n-j)! (n-2j-m)!} x^{(n-2j-m)}. \end{aligned},\]

where Legendre polynomials are defined as $P_n(x) = \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right]$. Note that $P_l^{-m} = (-1)^m \frac{(l-m)!}{(l+m)!} P_l^m$ for $m<0$. (It is not compatible with $P_k^m(t) = (-1)^m\left( 1-t^2 \right)^{m/2} \frac{\mathrm{d}^m P_k(t)}{\mathrm{d}t^m}$ caused by $(-1)^m$.) The specific formulae are given below.

Examples:

\[\begin{aligned} P_{0}^{0}(x) &= 1, \\ P_{1}^{0}(x) &= x, \\ P_{1}^{1}(x) &= \left(+1\right)\sqrt{1-x^2}, \\ P_{2}^{0}(x) &= -1/2 + 3/2 x^{2}, \\ P_{2}^{1}(x) &= \left(-3 x\right)\sqrt{1-x^2}, \\ P_{2}^{2}(x) &= 3 - 6 x, \\ P_{3}^{0}(x) &= -3/2 x + 5/2 x^{3}, \\ P_{3}^{1}(x) &= \left(3/2 - 15/2 x^{2}\right)\sqrt{1-x^2}, \\ P_{3}^{2}(x) &= 15 x - 30 x^{2}, \\ P_{3}^{3}(x) &= \left(15 - 30 x\right)\sqrt{1-x^2}, \\ P_{4}^{0}(x) &= 3/8 - 15/4 x^{2} + 35/8 x^{4}, \\ P_{4}^{1}(x) &= \left(- 15/2 x + 35/2 x^{3}\right)\sqrt{1-x^2}, \\ P_{4}^{2}(x) &= -15/2 + 15 x + 105/2 x^{2} - 105 x^{3}, \\ P_{4}^{3}(x) &= \left(105 x - 210 x^{2}\right)\sqrt{1-x^2}, \\ P_{4}^{4}(x) &= 105 - 420 x + 420 x^{2}, \\ & \vdots \end{aligned}\]

Antique.PMethod

P(model::SphericalOscillator, x; n=0, m=0)

Rodrigues' formula & closed-form:

\[\begin{aligned} P_n^m(x) &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} P_n(x) \\ &= \left( 1-x^2 \right)^{m/2} \frac{\mathrm{d}^m}{\mathrm{d}x^m} \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right] \\ &= \frac{1}{2^n} (1-x^2)^{m/2} \sum_{j=0}^{\left\lfloor\frac{n-m}{2}\right\rfloor} (-1)^j \frac{(2n-2j)!}{j! (n-j)! (n-2j-m)!} x^{(n-2j-m)}. \end{aligned},\]

where Legendre polynomials are defined as $P_n(x) = \frac{1}{2^n n!} \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left[ \left( x^2-1 \right)^n \right]$. Note that $P_l^{-m} = (-1)^m \frac{(l-m)!}{(l+m)!} P_l^m$ for $m<0$. (It is not compatible with $P_k^m(t) = (-1)^m\left( 1-t^2 \right)^{m/2} \frac{\mathrm{d}^m P_k(t)}{\mathrm{d}t^m}$ caused by $(-1)^m$.) The specific formulae are given below.

Examples:

\[\begin{aligned} P_{0}^{0}(x) &= 1, \\ P_{1}^{0}(x) &= x, \\ P_{1}^{1}(x) &= \left(+1\right)\sqrt{1-x^2}, \\ P_{2}^{0}(x) &= -1/2 + 3/2 x^{2}, \\ P_{2}^{1}(x) &= \left(-3 x\right)\sqrt{1-x^2}, \\ P_{2}^{2}(x) &= 3 - 6 x, \\ P_{3}^{0}(x) &= -3/2 x + 5/2 x^{3}, \\ P_{3}^{1}(x) &= \left(3/2 - 15/2 x^{2}\right)\sqrt{1-x^2}, \\ P_{3}^{2}(x) &= 15 x - 30 x^{2}, \\ P_{3}^{3}(x) &= \left(15 - 30 x\right)\sqrt{1-x^2}, \\ P_{4}^{0}(x) &= 3/8 - 15/4 x^{2} + 35/8 x^{4}, \\ P_{4}^{1}(x) &= \left(- 15/2 x + 35/2 x^{3}\right)\sqrt{1-x^2}, \\ P_{4}^{2}(x) &= -15/2 + 15 x + 105/2 x^{2} - 105 x^{3}, \\ P_{4}^{3}(x) &= \left(105 x - 210 x^{2}\right)\sqrt{1-x^2}, \\ P_{4}^{4}(x) &= 105 - 420 x + 420 x^{2}, \\ & \vdots \end{aligned}\]

Antique.RMethod

R(model::CoulombTwoBody, r; n=1, l=0)

\[R_{nl}(r) = -\sqrt{\frac{(n-l-1)!}{2n(n+l)!} \left(\frac{2Z}{n a_\mu}\right)^3} \left(\frac{2Zr}{n a_\mu}\right)^l \exp \left(-\frac{Zr}{n a_\mu}\right) L_{n+l}^{2l+1} \left(\frac{2Zr}{n a_\mu}\right),\]

where $\frac{1}{\mu} = \frac{1}{m_1}+\frac{1}{m_2}$, $a_\mu = a_0 \frac{m_\mathrm{e}}{\mu}$, Laguerre polynomials are defined as $L_n(x) = \frac{1}{n!} \mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right)$, and associated Laguerre polynomials are defined as $L_n^{k}(x) = \frac{\mathrm{d}^k}{\mathrm{d}x^k} L_n(x)$. Note that replace $2n(n+l)!$ with $2n[(n+l)!]^3$ if Laguerre polynomials are defined as $L_n(x) = \mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right)$. The domain is $0\leq r \lt \infty$.

Antique.RMethod

R(model::HydrogenAtom, r; n=1, l=0)

\[R_{nl}(r) = -\sqrt{\frac{(n-l-1)!}{2n(n+l)!} \left(\frac{2Z}{n a_0}\right)^3} \left(\frac{2Zr}{n a_0}\right)^l \exp \left(-\frac{Zr}{n a_0}\right) L_{n+l}^{2l+1} \left(\frac{2Zr}{n a_0}\right),\]

where Laguerre polynomials are defined as $L_n(x) = \frac{1}{n!} \mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right)$, and associated Laguerre polynomials are defined as $L_n^{k}(x) = \frac{\mathrm{d}^k}{\mathrm{d}x^k} L_n(x)$. Note that replace $2n(n+l)!$ with $2n[(n+l)!]^3$ if Laguerre polynomials are defined as $L_n(x) = \mathrm{e}^x \frac{\mathrm{d}^n}{\mathrm{d}x ^n} \left( \mathrm{e}^{-x} x^n \right)$. The domain is $0\leq r \lt \infty$.

Antique.RMethod

R(model::SphericalOscillator, r; n=0, l=0)

\[R_{nl}(r) = \sqrt{ \frac{\gamma^{3/2}}{2\sqrt{\pi}}} \sqrt{\frac{2^{n+l+3} n!}{(2n+2l+1)!!}} \xi^l \exp\left(-\xi^2/2\right)L_{n}^{(l+\frac{1}{2})} \left(\xi^2\right),\]

where $\gamma = \mu\omega/\hbar$ and $\xi = \sqrt{\gamma}r = \sqrt{\mu\omega/\hbar}r$ are defined. The generalized Laguerre polynomials are defined as $L_n^{(\alpha)}(x) = \frac{x^{-\alpha} \mathrm{e}^x}{n !} \frac{\mathrm{d}^n}{\mathrm{d} x^n}\left(\mathrm{e}^{-x} x^{n+\alpha}\right)$. The domain is $0\leq r \lt \infty$.

Antique.VMethod

V(model::CoulombTwoBody, r)

\[\begin{aligned} V(r) &= - \frac{Ze^2}{4\pi\varepsilon_0 r} &= - \frac{e^2}{4\pi\varepsilon_0 a_0} \frac{Z}{r/a_0} &= - \frac{Z}{r/a_0} E_\mathrm{h}, \end{aligned}\]

The domain is $0\leq r \lt \infty$.

Antique.VMethod

V(model::DeltaPotential, x)

\[V(x) = -\alpha \delta(x).\]

Antique.VMethod

V(model::HarmonicOscillator, x)

\[V(x) = \frac{1}{2} k x^2 = \frac{1}{2} m \omega^2 x^2 = \frac{1}{2} \hbar \omega \xi^2,\]

where $\omega = \sqrt{k/m}$ is the angular frequency and $\xi = \sqrt{\frac{m\omega}{\hbar}}x$.

Antique.VMethod

V(model::HydrogenAtom, r)

\[\begin{aligned} V(r) &= - \frac{Ze^2}{4\pi\varepsilon_0 r} &= - \frac{e^2}{4\pi\varepsilon_0 a_0} \frac{Z}{r/a_0} &= - \frac{Z}{r/a_0} E_\mathrm{h}, \end{aligned}\]

The domain is $0\leq r \lt \infty$.

Antique.VMethod

V(model::InfinitePotentialWell; x)

\[V(x) = \left\{ \begin{array}{ll} \infty & x \lt 0, L \lt x \\ 0 & 0 \leq x \leq L \end{array} \right.\]

Antique.VMethod

V(model::InfinitePotentialWell3D, x,y,z)

\[V(x,y,z) = \left\{ \begin{array}{ll} 0 & 0 \leq x \leq L_x \ \mathrm{and}\ 0 \leq y \leq L_y \ \mathrm{and}\ 0 \leq z \leq L_z \\ \infty & \mathrm{elsewhere} \end{array} \right.\]

Antique.VMethod

V(model::MorsePotential, r)

\[V(r) = D_\mathrm{e} \left( \mathrm{e}^{-2a(r-r_e)} - 2\mathrm{e}^{-a(r-r_e)} \right),\]

where $a = \sqrt{\frac{k}{2Dₑ}}$ is defined. The domain is $0\leq r \lt \infty$.

Antique.VMethod

V(model::PoschlTeller, x)

\[\begin{aligned} V(x) &= -\frac{\hbar^2}{m x_0^2} \frac{\lambda(\lambda+1)}{2} \mathrm{sech}(x)^2 &= -\frac{\hbar^2}{m x_0^2} \frac{\lambda(\lambda+1)}{2} \frac{1}{\mathrm{cosh}(x)^2}. \end{aligned}\]

Antique.VMethod

V(model::RigidRotor, r)

\[\begin{aligned} V(r) &= 0, \end{aligned}\]

Antique.VMethod

V(model::SphericalOscillator, r)

\[V(r) = \frac{1}{2} k r^2 = \frac{1}{2} \mu \omega^2 r^2 = \frac{1}{2} \hbar \omega \xi^2,\]

where $\omega = \sqrt{k/\mu}$ is the angular frequency and $\xi = \sqrt{\frac{\mu\omega}{\hbar}}r$.

Antique.YMethod

Y(model::CoulombTwoBody, θ, φ; l=0, m=0)

\[Y_{lm}(\theta,\varphi) = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{2l+1}{4\pi} \frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} (\cos\theta) \mathrm{e}^{im\varphi}.\]

The domain is $0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$. Note that some variants are connected by

\[i^{|m|+m} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^m \sqrt{\frac{(l-m)!}{(l+m)!}} P_l^{m}.\]

Antique.YMethod

Y(model::HydrogenAtom, θ, φ; l=0, m=0)

\[Y_{lm}(\theta,\varphi) = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{2l+1}{4\pi} \frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} (\cos\theta) \mathrm{e}^{im\varphi}.\]

The domain is $0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$. Note that some variants are connected by

\[i^{|m|+m} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^m \sqrt{\frac{(l-m)!}{(l+m)!}} P_l^{m}.\]

Antique.YMethod

Y(model::RigidRotor, θ, φ; l=0, m=0)

\[Y_{lm}(\theta,\varphi) = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{2l+1}{4\pi} \frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} (\cos\theta) \mathrm{e}^{im\varphi}.\]

The domain is $0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$. Note that some variants are connected by

\[i^{|m|+m} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^m \sqrt{\frac{(l-m)!}{(l+m)!}} P_l^{m}.\]

Antique.YMethod

Y(model::SphericalOscillator, θ, φ; l=0, m=0)

\[Y_{lm}(\theta,\varphi) = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{2l+1}{4\pi} \frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} (\cos\theta) \mathrm{e}^{im\varphi}.\]

The domain is $0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$. Note that some variants are connected by

\[i^{|m|+m} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^{\frac{|m|+m}{2}} \sqrt{\frac{(l-|m|)!}{(l+|m|)!}} P_l^{|m|} = (-1)^m \sqrt{\frac{(l-m)!}{(l+m)!}} P_l^{m}.\]

Antique.nₘₐₓMethod

nₘₐₓ(model::MorsePotential)

\[n_\mathrm{max} = \left\lfloor \frac{2 D_e - \omega}{\omega} \right\rfloor,\]

where $\omega = \sqrt{k/µ}$ is defined.

Antique.nₘₐₓMethod

nₘₐₓ(model::PoschlTeller)

\[n_\mathrm{max} = \left\lfloor \lambda \right\rfloor - 1.\]

Antique.ψMethod

ψ(model::CoulombTwoBody, r, θ, φ; n=1, l=0, m=0)

\[\psi_{nlm}(\pmb{r}) = R_{nl}(r) Y_{lm}(\theta,\varphi)\]

The domain is $0\leq r \lt \infty, 0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$.

Antique.ψMethod

ψ(model::DeltaPotential, x)

\[\psi(x) = \frac{\sqrt{m\alpha}}{\hbar} \mathrm{e}^{-m\alpha |x|/\hbar^2}\]

Antique.ψMethod

ψ(model::HarmonicOscillator, x; n=0)

\[\psi_n(x) = A_n H_n(\xi) \exp{\left( -\frac{\xi^2}{2} \right)},\]

where $\omega = \sqrt{k/m}$, $\xi = \sqrt{\frac{m\omega}{\hbar}}x$, $A_n = \sqrt{\frac{1}{n! 2^n} \sqrt{\frac{m\omega}{\pi\hbar}}}$, $H_n(x) = (-1)^n \mathrm{e}^{x^2} \frac{\mathrm{d}^n}{\mathrm{d}x^n} \mathrm{e}^{-x^2}$ are defined.

Antique.ψMethod

ψ(model::HydrogenAtom, r, θ, φ; n=1, l=0, m=0)

\[\psi_{nlm}(\pmb{r}) = R_{nl}(r) Y_{lm}(\theta,\varphi)\]

The domain is $0\leq r \lt \infty, 0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$.

Antique.ψMethod

ψ(model::InfinitePotentialWell, x; n=1)

\[\psi_n(x) = \sqrt{\frac{2}{L}} \sin \frac{n\pi x}{L}\]

Antique.ψMethod

ψ(model::InfinitePotentialWell3D, x,y,z; nx=1, ny=1, nz=1)

The wave functions can be expressed as products of wave functions in a one-dimensional box.

\[\psi_{n_x,n_y,n_z}(x,y,z) = \psi_{n_x}(x)\psi_{n_y}(y)\psi_{n_z}(z) = \sqrt{\frac{8}{L_xL_yL_z}} \sin\left(\frac{n_x\pi x}{L_x}\right) \sin\left(\frac{n_y\pi y}{L_y}\right) \sin\left(\frac{n_z\pi z}{L_z}\right)\]

Antique.ψMethod

ψ(model::MorsePotential, r; n=0)

\[\psi_n(r) = N_n z^{\lambda-n-1/2} \mathrm{e}^{-z/2} L_n^{(2\lambda-2n-1)}(\xi),\]

$N_n = \sqrt{\frac{n!(2\lambda-2n-1)a}{\Gamma(2\lambda-n)}}$, $\lambda = \frac{\sqrt{2\mu D_\mathrm{e}}}{a\hbar}$, $a = \sqrt{\frac{k}{2Dₑ}}$, $L_n^{(\alpha)}(x) = \frac{x^{-\alpha} \mathrm{e}^x}{n !} \frac{\mathrm{d}^n}{\mathrm{d} x^n}\left(\mathrm{e}^{-x} x^{n+\alpha}\right)$, $\xi := 2\lambda\mathrm{e}^{-a(r-r_e)}$ are defined. The domain is $0\leq r \lt \infty$.

Antique.ψMethod

ψ(model::PoschlTeller, x; n=0)

\[\psi_n(x) = P_\lambda^{\mu}(\mathrm{tanh}(x/x_0)) \sqrt{\mu\frac{\Gamma(\lambda-\mu+1)}{\Gamma(\lambda+\mu+1)}},\]

where $\mu = \mu(n) = n_\mathrm{max}-n+1$, and $n_\mathrm{max} = \left\lfloor \lambda \right\rfloor - 1$ and $P_\lambda^{\mu}$ are the associated Legendre functions.

Antique.ψMethod

ψ(model::RigidRotor, θ, φ; l=0, m=0)

\[\psi_{lm}(\theta,\varphi) = Y_{lm}(\theta,\varphi)\]

The wave function is the spherical harmonics. The domain is $0\leq \theta \lt \pi$ and $0\leq \varphi \lt 2\pi$.

Antique.ψMethod

ψ(model::SphericalOscillator, r, θ, φ; n=0, l=0, m=0)

\[\psi_{nlm}(\pmb{r}) = R_{nl}(r) Y_{lm}(\theta,\varphi)\]

The domain is $0\leq r \lt \infty, 0\leq \theta \lt \pi, 0\leq \varphi \lt 2\pi$.