import numpy as np
from pyscf import gto, scf, mp

# Define a molecule using pyscf library
mol = gto.Mole()
mol.atom = '''
O 0.0000000 0.0000000 0.0000000
H 0.7570000 0.5860000 0.0000000
H -0.7570000 0.5860000 0.0000000
'''
mol.basis = 'sto-3g'
mol.build()

# Generate random coordinates and charges for MM particles
num_particles = 10
mm_coordinates = np.random.rand(num_particles, 3)
mm_charges = np.random.rand(num_particles)

# Define a function to calculate the force
def calculate_force_qm_mm(qm_density, mm_coordinates, mm_charges):
    qm_mm_force = np.zeros_like(mm_coordinates)
    
    # Calculate force from QM atoms and MM particles interaction
    
    # Calculate force from electron density and MM particles interaction
    
    return qm_mm_force

# Calculate force from Hartree-Fock electron density
mf = scf.RHF(mol)
mf.kernel()
hf_density = mf.make_rdm1()
force_hf = calculate_force_qm_mm(hf_density, mm_coordinates, mm_charges)

# Define a function to make the reduced density matrix with orbital response
def make_rdm1_with_orbital_response(mf, mo_energy, mo_coeff, mo_occ):
    rdm1 = np.zeros((mol.nao, mol.nao))
    
    # Calculate rdm1 with orbital response
    
    return rdm1

# Calculate force from MP2 electron density with orbital response
mp2 = mp.MP2(mf)
mp2.kernel()
mo_energy = mp2.mo_energy
mo_coeff = mp2.mo_coeff
mo_occ = mp2.mo_occ
rdm1_orbital_response = make_rdm1_with_orbital_response(mf, mo_energy, mo_coeff, mo_occ)
force_mp2 = calculate_force_qm_mm(rdm1_orbital_response, mm_coordinates, mm_charges)