Integrators and Ensembles#

Monte Carlo Barostat#

The Monte Carlo barostat proposes trial changes to the periodic box and accepts or rejects them using the Metropolis criterion.

Supported pressure modes: ISO, SEMI, and ANISO.

Berendsen Barostat#

The Berendsen barostat [4] couples the periodic box to an external pressure bath by rescaling the box and coordinates.

Supported pressure modes: ISO, SEMI, and ANISO.

Bussi Barostat#

The Bussi barostat implements the Bernetti–Bussi stochastic cell-rescaling method [5]. It rescales the periodic box, coordinates, and velocities to control pressure.

Supported pressure modes: ISO, SEMI, and ANISO.

Verlet Integrator#

RESPA Integrator#

Extended Nosé-Hoover Chain#

Supported pressure mode: ISO only.

Authors of paper [6] (MTK) discussed several methods for NVT and NPT ensembles.

Number

Sections in MTK

Method

1a

2.1 4.3

NVT

2a

2.2 4.4

NPT (isotropic cell fluctuations)

3a

2.3 4.5

NPT (full cell fluctuations)

4a

5.2

XO-RESPA

4b

5.2

XI-RESPA

1b

5.3

RESPA 1a

2b

5.4

RESPA 2a

3b

5.4

RESPA 3a

The isothermal-isobaric integrator implemented in Fortran Tinker and here is NPT-XO (#2a-4a).

Tip

Nosé-Hoover Chain can be enabled by keywords

integrator nose-hoover

or

thermostat nose-hoover
barostat   nose-hoover

with the NPT option in the dynamic program.

Langevin Piston#

Supported pressure mode: ISO only.

The Langevin piston method for constant pressure [7] is integrated in the Leapfrog framework.

Tip

Langevin Piston can be enabled by keywords

integrator lpiston

or

thermostat lpiston
barostat   lpiston

with the NPT option in the dynamic program.