libint2::Shell Struct Reference

generally-contracted Solid-Harmonic/Cartesion Gaussian Shell More...

#include <shell.h>

Classes
struct	Contraction
	contracted Gaussian = angular momentum + sph/cart flag + contraction coefficients More...
struct	defaultable_boolean

Public Types
typedef double	real_t

Public Member Functions
	Shell (const Shell &)=default
	Shell (Shell &&other) noexcept
Shell &	operator= (const Shell &)=default
Shell &	operator= (Shell &&other) noexcept
	Shell (svector< real_t > _alpha, svector< Contraction > _contr, std::array< real_t, 3 > _O, bool embed_normalization_into_coefficients=true)
Shell &	move (std::array< real_t, 3 > new_origin)
size_t	cartesian_size () const
size_t	size () const
size_t	ncontr () const
size_t	nprim () const
bool	operator== (const Shell &other) const
bool	operator!= (const Shell &other) const
real_t	coeff_normalized (size_t c, size_t p) const
Shell	extract_primitive (size_t p, bool unit_normalized=true) const
	extract primitive shell

Static Public Member Functions
static char	am_symbol (size_t l)
static unsigned short	am_symbol_to_l (char am_symbol)
	inverse of am_symbol()
static bool	do_enforce_unit_normalization (defaultable_boolean flag=defaultable_boolean())
	sets and/or reports whether the auto-renormalization to unity is set if called without arguments, returns the current value of the flag otherwise, will set the flag to flag
static const Shell &	unit ()

Public Attributes
svector< real_t >	alpha
	exponents
svector< Contraction >	contr
	contractions
std::array< real_t, 3 >	O
	origin
svector< real_t >	max_ln_coeff
	maximum ln of (absolute) contraction coefficient for each primitive

Detailed Description

generally-contracted Solid-Harmonic/Cartesion Gaussian Shell

A simple-to-use Gaussian shell. Here's an example of how to create an s+p shell of the STO-3G basis on the oxygen atom located at the origin.

*  auto s = Shell{
*                  {5.033151300, 1.169596100, 0.380389000},
*                  {
*                    {0, false, {-0.09996723, 0.39951283, 0.70011547}},
*                    {1, false, {0.15591627, 0.60768372, 0.39195739}}
*                  },
*                   {{0.0, 0.0, 0.0}}
*                };
*  

Note

The contraction coefficients correspond to unity-normalized primitives. EMSL Gaussian Basis Set Database, as well as basis set libraries embedded into most quantum chemistry programs use this convention. However, coefficients are automatically converted internally to refer to normalization-free primitives before computing integrals (see Shell::renorm() ).

Constructor & Destructor Documentation

Shell()

libint2::Shell::Shell ( svector< real_t > _alpha, svector< Contraction > _contr, std::array< real_t, 3 > _O, bool embed_normalization_into_coefficients = true )

inline

Parameters

embed_normalization_into_coefficients

if true, will embed normalization factors into coefficients, else will use the coefficients in _contr as given

Member Function Documentation

am_symbol()

static char libint2::Shell::am_symbol ( size_t l )

inlinestatic

Parameters

l	angular momentum quantum number

Returns

(lower-case) letter symbol corresponding to l ; e.g., s for l=0, p for l=1, etc.

Exceptions

std::invalid_argument

if l is greater than 20

Referenced by am_symbol_to_l(), and libint2::molden::Export::write_basis().

am_symbol_to_l()

static unsigned short libint2::Shell::am_symbol_to_l ( char am_symbol )

inlinestatic

inverse of am_symbol()

Parameters

am_symbol

letter symbol denoting orbital angular momentum l ; e.g., s for l=0, p for l=1, etc.

Note

this function is case insensitive, i.e. ‘am_symbol_to_l('s’) == am_symbol_to_l('S')`

Returns

angular momentum quantum number

See also

am_symbol()

References am_symbol().

coeff_normalized()

real_t libint2::Shell::coeff_normalized ( size_t c, size_t p ) const

inline

Returns

the coefficient of primitive p in contraction c assuming unit normalized primitive (coeff contains coefficients of normalization-free primitives;

See also

Shell::renorm() )

References alpha, and contr.

Referenced by libint2::molden::Export::write_basis().

do_enforce_unit_normalization()

static bool libint2::Shell::do_enforce_unit_normalization ( defaultable_boolean flag = defaultable_boolean() )

inlinestatic

sets and/or reports whether the auto-renormalization to unity is set if called without arguments, returns the current value of the flag otherwise, will set the flag to flag

Note

by default, shells WILL be re-normalized to unity

extract_primitive()

Shell libint2::Shell::extract_primitive ( size_t p, bool unit_normalized = true ) const

inline

extract primitive shell

Parameters

p	the index of the primitive to extract
unit_normalized	whether to produce unit-normalized primitive; set to false to produce normalization-free primitive

Returns

a primitive Shell

References alpha, contr, and O.

unit()

static const Shell & libint2::Shell::unit ( )

inlinestatic

Returns

"unit" Shell, with exponent=0. and coefficient=1., located at the origin

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The documentation for this struct was generated from the following file:

• shell.h