Welcome to ACPYPE’s documentation!

ACPYPE - AnteChamber PYthon Parser interfacE

A tool based in Python to use Antechamber to generate topologies for chemical compounds and to interface with others python applications like CCPN and ARIA. Topologies files to be generated so far: CNS/XPLOR, GROMACS, CHARMM and AMBER.

Quick start

acpype has two modes, and both are a single command.

From a small molecule – a .mol2, .pdb, .mdl/.mol file, or a SMILES string – it drives the whole AmberTools pipeline:

acpype -i molecule.mol2 -b MOL -c bcc -n 0 -a gaff2

That single command does the work of three separate AmberTools runs – antechamber to assign atom types and charges, parmchk2 to fill in missing parameters, and tleap to build the topology – and then also writes GROMACS, CNS/XPLOR and CHARMM versions into one MOL.acpype/ folder.

From existing AMBER files, converting a LEaP prmtop/inpcrd pair to GROMACS without needing AmberTools at all:

acpype -p FFF_AC.prmtop -x FFF_AC.inpcrd

Run acpype -h for every option and a description of each output file. The README covers installation and worked examples for GROMACS, CNS/XPLOR and NAMD.

Using ACPYPE as a library

acpype.acs_api.acpype_api returns the generated topologies as a JSON string, and acpype.topol.ACTopol exposes the same pipeline as an object:

from acpype.topol import ACTopol

molecule = ACTopol("molecule.mol2", chargeType="bcc", atomType="gaff2", basename="MOL")
molecule.createACTopol()
molecule.createMolTopol()

The full API is documented below.

API reference

acpype

The Package

Indices and tables