Merge pull request #298 from zincware/velocity-verlet-dynamics

implements ase velocity verlet dynamics

Author: Tetracarbonylnickel

ipsuite/calculators/__init__.pyi

@@ -11,6 +11,7 @@ from .ase_md import (
     RescaleBoxModifier,
     TemperatureOscillatingRampModifier,
     TemperatureRampModifier,
+    VelocityVerletDynamic,
 )
 from .ase_standard import EMTSinglePoint, LJSinglePoint
 from .cp2k import CP2KSinglePoint, CP2KYaml
@@ -29,6 +30,7 @@ __all__ = [
     "xTBSinglePoint",
     "LJSinglePoint",
     "LangevinThermostat",
+    "VelocityVerletDynamic",
     "ApaxJaxMD",
     "RescaleBoxModifier",
     "BoxOscillatingRampModifier",

ipsuite/calculators/ase_md.py

@@ -15,6 +15,7 @@
 from ase.md.langevin import Langevin
 from ase.md.npt import NPT
 from ase.md.velocitydistribution import MaxwellBoltzmannDistribution
+from ase.md.verlet import VelocityVerlet
 from tqdm import trange
 
 from ipsuite import base
@@ -276,6 +277,25 @@ def get_thermostat(self, atoms):
         return thermostat
 
 
+class VelocityVerletDynamic(base.IPSNode):
+    """Initialize the Velocity Verlet dynamics
+
+    Attributes
+    ----------
+    time_step: float
+        time step of simulation
+    """
+
+    time_step: int = zntrack.params()
+
+    def get_thermostat(self, atoms):
+        dyn = VelocityVerlet(
+            atoms=atoms,
+            timestep=self.time_step * units.fs,
+        )
+        return dyn
+
+
 class NPTThermostat(base.IPSNode):
     """Initialize the ASE NPT barostat
     (Nose Hoover temperature coupling + Parrinello Rahman pressure coupling).

ipsuite/nodes.py

@@ -94,6 +94,7 @@ class _Nodes:
     MixCalculator = "ipsuite.calculators.MixCalculator"
 
     LangevinThermostat = "ipsuite.calculators.LangevinThermostat"
+    VelocityVerletDynamic = "ipsuite.calculators.VelocityVerletDynamic"
     NPTThermostat = "ipsuite.calculators.NPTThermostat"
     RescaleBoxModifier = "ipsuite.calculators.RescaleBoxModifier"
     BoxOscillatingRampModifier = "ipsuite.calculators.BoxOscillatingRampModifier"