Feature List

This page summarizes the main features supported by PQ. Planned items are listed separately so they are not confused with currently available run modes.

Run Modes

The supported jobtype values are:

• mm-md - molecular-mechanics molecular dynamics

• qm-md - quantum-mechanics molecular dynamics

• qm-rpmd - quantum-mechanics ring-polymer molecular dynamics

• qmmm-md - hybrid quantum mechanics - molecular mechanics molecular dynamics

• mm-opt - molecular-mechanics geometry optimization

• mm-hessian - molecular mechanics Hessian calculation

Molecular Mechanics

Force-field models

• GUFF (Grand Unified Force Field)

• AMBER-type force fields with force-field

• Lennard-Jones, Buckingham and Morse non-Coulombic interactions

Force evaluation

• brute-force pair evaluation

• cell-list pair evaluation

Long-range corrections

• no correction

• Reaction field

• Wolf summation

Quantum Mechanics

Supported QM runners

• DFTB+

• Turbomole

• PySCF

• FeNNol

• MACE-MP and MACE-OFF

• ASE-DFTB+

• ASE-xTB

Molecular Dynamics

Integrator

• Velocity Verlet

Thermostats

• Langevin

• Berendsen

• stochastic velocity rescaling

• Nose-Hoover chain

Manostats

• Berendsen

• stochastic cell rescaling

Cell coupling modes

• isotropic

• semi-isotropic

• anisotropic cell lengths

• full anisotropic cell lengths and angles

Constraints

• SHAKE/RATTLE

• M-SHAKE

• distance constraints

Optimization

Geometry optimization is available for molecular-mechanics calculations. The supported optimizers are:

• steepest descent

• ADAM

MPI

MPI support is used for QM-RPMD, where individual ring-polymer beads can be distributed across ranks. Force evaluation itself remains local to each rank, except for external QM programs that provide their own parallel execution.

Planned Items

The following items are planned for future releases:

• MM-RPMD

• Verlet-list force evaluation

• Ewald summation

• LINCS constraints