Lightweight POD struct for multipole coordinate system transformations. More...

#include <coordinate_system.h>

Public Member Functions
Vec3	raxyz () const
Vec3	rbxyz () const
double	rax () const
double	ray () const
double	raz () const
double	rbx () const
double	rby () const
double	rbz () const
double	dx () const
double	dy () const
double	dz () const
double	raw_rax () const
double	raw_ray () const
double	raw_raz () const
double	raw_rbx () const
double	raw_rby () const
double	raw_rbz () const
bool	is_valid (double tolerance=1e-12) const
	Validate coordinate system consistency Returns true if all computed quantities are consistent.
bool	matches_orient_debug (double orient_rax, double orient_ray, double orient_raz, double orient_rbx, double orient_rby, double orient_rbz, double orient_r, double tolerance=1e-6) const
	Check if coordinate system matches Orient's debug output Useful for validating against known Orient calculations.

Static Public Member Functions
static CoordinateSystem	from_points (const Vec3 &ra_in, const Vec3 &rb_in)
	Initialize coordinate system from two points Following Orient's mlinfo.f90 exactly:
static CoordinateSystem	from_body_frame (const Vec3 &ra_in, const Vec3 &rb_in, const Mat3 &M_A, const Mat3 &M_B)
	Initialize coordinate system with body-frame unit vectors (Orient's approach).

Public Attributes
Vec3	ra
Vec3	rb
Vec3	rab
double	r
Vec3	er
bool	use_body_frame = false
Vec3	e1r_body
Vec3	e2r_body
double	cxx
double	cxy
double	cxz
double	cyx
double	cyy
double	cyz
double	czx
double	czy
double	czz

Detailed Description

Lightweight POD struct for multipole coordinate system transformations.

Coordinate definitions:

Site A coordinates: ra (raw input coordinates)
Site B coordinates: rb (raw input coordinates)
Inter-site vector: rab = rb - ra
Distance: r = |rab|
Unit vector: er = rab / r (points from A to B)

OCC convention for unit vector accessors: rax,ray,raz = +er (unit vector from A to B) rbx,rby,rbz = -er (unit vector from B to A)

Note: Orient uses the OPPOSITE sign convention: Orient rax = -er, Orient rbx = +er The S-function kernel code compensates by swapping which accessor it calls (e.g., using rbx() where Orient uses rax), so the numerical results match Orient exactly despite the naming difference.

Member Function Documentation

◆ dx()

double occ::mults::CoordinateSystem::dx ( ) const

inline

◆ dy()

double occ::mults::CoordinateSystem::dy ( ) const

inline

◆ dz()

double occ::mults::CoordinateSystem::dz ( ) const

inline

◆ from_body_frame()

CoordinateSystem occ::mults::CoordinateSystem::from_body_frame	(	const Vec3 &	ra_in,
		const Vec3 &	rb_in,
		const Mat3 &	M_A,
		const Mat3 &	M_B )

inlinestatic

Initialize coordinate system with body-frame unit vectors (Orient's approach).

This implements Orient's body-frame approach where:

Lab frame: er_lab = (rb - ra) / |rb - ra|
Body frame for site A: e1r = M_A^T * er_lab
Body frame for site B: e2r = -M_B^T * er_lab
Orientation matrix: xx = M_A^T * M_B

Parameters

ra_in	Position of site A (lab frame)
rb_in	Position of site B (lab frame)
M_A	Rotation matrix for molecule A (body to lab)
M_B	Rotation matrix for molecule B (body to lab)

◆ from_points()

CoordinateSystem occ::mults::CoordinateSystem::from_points	(	const Vec3 &	ra_in,
		const Vec3 &	rb_in )

inlinestatic

Initialize coordinate system from two points Following Orient's mlinfo.f90 exactly:

rab = rb - ra (site-to-site vector)
r = |rab| (distance)
er = rab / r (normalized inter-site vector)
Orientation matrix initialized to identity (for point multipoles)

◆ is_valid()

bool occ::mults::CoordinateSystem::is_valid ( double tolerance = 1e-12 ) const

inline

Validate coordinate system consistency Returns true if all computed quantities are consistent.

◆ matches_orient_debug()

bool occ::mults::CoordinateSystem::matches_orient_debug	(	double	orient_rax,
		double	orient_ray,
		double	orient_raz,
		double	orient_rbx,
		double	orient_rby,
		double	orient_rbz,
		double	orient_r,
		double	tolerance = 1e-6 ) const

inline

Check if coordinate system matches Orient's debug output Useful for validating against known Orient calculations.

◆ raw_rax()

double occ::mults::CoordinateSystem::raw_rax ( ) const

inline

◆ raw_ray()

double occ::mults::CoordinateSystem::raw_ray ( ) const

inline

◆ raw_raz()

double occ::mults::CoordinateSystem::raw_raz ( ) const

inline

◆ raw_rbx()

double occ::mults::CoordinateSystem::raw_rbx ( ) const

inline

◆ raw_rby()

double occ::mults::CoordinateSystem::raw_rby ( ) const

inline

◆ raw_rbz()

double occ::mults::CoordinateSystem::raw_rbz ( ) const

inline

◆ rax()

double occ::mults::CoordinateSystem::rax ( ) const

inline

◆ raxyz()

Vec3 occ::mults::CoordinateSystem::raxyz ( ) const

inline

◆ ray()

double occ::mults::CoordinateSystem::ray ( ) const

inline

◆ raz()

double occ::mults::CoordinateSystem::raz ( ) const

inline

◆ rbx()

double occ::mults::CoordinateSystem::rbx ( ) const

inline

◆ rbxyz()

Vec3 occ::mults::CoordinateSystem::rbxyz ( ) const

inline

◆ rby()

double occ::mults::CoordinateSystem::rby ( ) const

inline

◆ rbz()

double occ::mults::CoordinateSystem::rbz ( ) const

inline

Member Data Documentation

◆ cxx

double occ::mults::CoordinateSystem::cxx

◆ cxy

double occ::mults::CoordinateSystem::cxy

◆ cxz

double occ::mults::CoordinateSystem::cxz

◆ cyx

double occ::mults::CoordinateSystem::cyx

◆ cyy

double occ::mults::CoordinateSystem::cyy

◆ cyz

double occ::mults::CoordinateSystem::cyz

◆ czx

double occ::mults::CoordinateSystem::czx

◆ czy

double occ::mults::CoordinateSystem::czy

◆ czz

double occ::mults::CoordinateSystem::czz

◆ e1r_body

Vec3 occ::mults::CoordinateSystem::e1r_body

◆ e2r_body

Vec3 occ::mults::CoordinateSystem::e2r_body

◆ er

Vec3 occ::mults::CoordinateSystem::er

◆ r

double occ::mults::CoordinateSystem::r

◆ ra

Vec3 occ::mults::CoordinateSystem::ra

◆ rab

Vec3 occ::mults::CoordinateSystem::rab

◆ rb

Vec3 occ::mults::CoordinateSystem::rb

◆ use_body_frame

bool occ::mults::CoordinateSystem::use_body_frame = false

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

/home/runner/work/occ/occ/include/occ/mults/coordinate_system.h

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation

◆ dx()

◆ dy()

◆ dz()

◆ from_body_frame()

◆ from_points()

◆ is_valid()

◆ matches_orient_debug()

◆ raw_rax()

◆ raw_ray()

◆ raw_raz()

◆ raw_rbx()

◆ raw_rby()

◆ raw_rbz()

◆ rax()

◆ raxyz()

◆ ray()

◆ raz()

◆ rbx()

◆ rbxyz()

◆ rby()

◆ rbz()

Member Data Documentation

◆ cxx

◆ cxy

◆ cxz

◆ cyx

◆ cyy

◆ cyz

◆ czx

◆ czy

◆ czz

◆ e1r_body

◆ e2r_body

◆ er

◆ r

◆ ra

◆ rab

◆ rb

◆ use_body_frame