MgridSystem_tag Struct Reference

Helper class to provide and return results from Mgrid_tag class. More...

#include <mgrid.h>

List of all members.

Public Attributes
double	u_elec
double	u_short
double	u_long
MD_Dvec *	f_elec
MD_Dvec *	f_short
MD_Dvec *	f_long
MD_Dvec *	pos
double *	charge
int32 **	excl_list
int32 **	scaled14_list
double	scaling14

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Detailed Description

Helper class to provide and return results from Mgrid_tag class.

User sets the internal fields of this class in order to provide data to Mgrid_tag class and receive its results. The user retains ownership of the arrays. The arrays are of length MgridParam_tag::natoms.

Input:
The pos and charge arrays must be provided. The atomic positions in pos must map into the cubic domain defined by MgridParam_tag. For periodic simulations, this means that they might have to be "wrapped" back into the box. Depending on the desired units, the atomic charges supplied to the charge array will need to be weighted by the square root of the conversion constant.

Optional input:
The excl_list and scaled14_list are jagged arrays as defined by the force library. These are supplied if the user wishes the mgrid library to compute electrostatic exclusions, along with scaling14 multiplicative constant if applicable. All things considered, there is no discernible numerical advantage to having electrostatic exclusions subtracted out sooner rather later, so it is probably best to just have the force library deal with it.

Output:
The electrostatic potential energy is returned in u_elec, the sum of the short-range part u_short and the long-range part u_long. The array f_elec designated to receive the electrostatic forces must be provided. The arrays f_short and f_long provide, respectively, the short-range and long-range parts of the force for each atom, intended for diagnostic purposes.

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Member Data Documentation

double* MgridSystem_tag::charge

Atomic charges, likely to be weighted by the square root of the unit conversion constant.

int32** MgridSystem_tag::excl_list

List of nonbonded exclusions as returned by the Force_tag class method force_excl_list(). Only provide this if you wish Mgrid_tag to deal with nonbonded electrostatic exclusions.

MD_Dvec* MgridSystem_tag::f_elec

Atomic forces due to the electrostatic potential energy.

MD_Dvec* MgridSystem_tag::f_long

Contribution to the forces from the long-range part, this array is optional.

MD_Dvec* MgridSystem_tag::f_short

Contribution to the forces from the short-range part, this array is optional.

MD_Dvec* MgridSystem_tag::pos

Atomic positions, must be within cubic domain.

int32** MgridSystem_tag::scaled14_list

List of scaled 1-4 interactions as returned by the Force_tag class method force_scaled14_list(). Only provide this if you wish Mgrid_tag to deal with scaled 1-4 electrostatic interactions.

double MgridSystem_tag::scaling14

Multiplicative constant for scaled 1-4 electrostatic interactions, set to ForceParam_tag::scaling14. Only provide this if you wish Mgrid_tag to deal with scaled 1-4 electrostatic interactions.

double MgridSystem_tag::u_elec

Electrostatic potential energy.

double MgridSystem_tag::u_long

Contribution to the potential from the long-range part.

double MgridSystem_tag::u_short

Contribution to the potential from the short-range part.

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

• mgrid/mgrid.h

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