mstk.forcefield.LJ126Term

class mstk.forcefield.LJ126Term(type1, type2, epsilon, sigma)

vdW term in LJ-12-6 function form.

The energy function is

>>> U = 4*epsilon*((sigma/r)^12-(sigma/r)^6)

LJ126 is commonly used, therefore we don’t generalize it with MieTerm.

During the initialization, the two atom types will be sorted by their string.

Parameters:

• type1 (str) –

• type2 (str) –

• epsilon (float) –

• sigma (float) –

type1

Type:

str

type2

Type:

str

epsilon

Type:

float

sigma

Type:

float

Methods

__init__(type1, type2, epsilon, sigma)
evaluate_energy(r)	Evaluate the energy for a force field term like HarmonicBondTerm, PeriodicDihedralTerm, etc...
get_alias()	Return a short alias for the name of this class
to_zff()	Pack the attributes of a term into a string so that can be saved into a line in ZFF file.
to_zff_header()	Header string to explain a line in ZFF format
to_zfp()	Pack the attributes of a term into a dict so that can be saved into ZFP xml file.

Attributes

name	The name of this force field term.

evaluate_energy(r)

Evaluate the energy for a force field term like HarmonicBondTerm, PeriodicDihedralTerm, etc…

It is mainly for debugging. It is not (and can not be) implemented for all terms.

Parameters:

val (float) – The value of distance, angle, dihedral or improper.

Returns:

energy

Return type:

float