from ase.build import molecule from ase.calculators.empirical_potentials import G2Potential from ase.optimize import BFGS # Create Methane molecule ethane = molecule('C2H6') # Set up calculator using G2Potential calc = G2Potential() # Attach calculator object to ethane ethane.set_calculator(calc) # Optimize the geometry to find the minimum energy state BFGS(ethane).run() # Retrieve forces for ethane system ethane_forces = ethane.get_forces() # Print forces on first atom in ethane print(ethane_forces[0])
from ase import Atoms from ase.calculators.emt import EMT # Create system of 10 helium atoms with random positions helium_system = Atoms('He10', positions=np.random.rand(10, 3)) # Set up calculator using EMT potential calc = EMT() # Attach calculator object to helium system helium_system.set_calculator(calc) # Retrieve forces for the helium system helium_forces = helium_system.get_forces() # Print forces on each atom in the helium system for index, force in enumerate(helium_forces): print(f'Force on atom {index}: {force}')Output: The code will output the forces acting on each helium atom in the system. In conclusion, the described function and code examples use the Python ase package/library, which is designed for atomistic simulations and manipulation of atoms. The ASE package provides an API to different simulation packages such as VASP, GULP, and LAMMPS, and the atoms.get_forces function retrieves the forces acting on each atom in the system.