Atom

This class stores all properties (attributes) related to an atom. When pmx reads a PDB file, each line starting with “ATOM” or “HETATM” is converted to an Atom instance. In addition, the atom class also has a number of methods that can be used to calculate distances, angles and dihedrals.

API Reference

class pmx.atom.Atom(line=None, mol2line=None, **kwargs)

Atom Class.

Parameters
  • line (str, optional) – input line in PDB format. Default is None.

  • mol2line (str, optional) – input line in MOL2 format. Default is None.

id

atom id

Type

int

name

atom name

Type

str

resname

name of residue atom is part of

Type

str

chain_id

ID of the chain atom belongs to

Type

str

x

atom coordinates

Type

array

occ

occupancy

Type

float

bfac

B-factor

Type

float

symbol

chemical element of the atom

Type

str

unity

unit of the coordinates, either ‘A’ or ‘nm’. Default is ‘A’.

Type

str

Methods

dist(other)

Calculates the distance between two atoms.

dist2(other)

Calculates the squared distance between two atoms.

translate(v)

Translates the position of the atom.

angle(other1, other2[, degree])

Calcluates the angle between 3 atoms.

dihedral(other1, other2, other3[, degree])

Calculates the dihedral angle between four atoms.

nm2a()

Converts the Atom coordinates from nanometers (nm) to Angstrom (A).

a2nm()

Converts the Atom coordinates from Angstrom (A) to nanometers (nm).