QM/MM Simulation Service

The QM/MM method is used to deal with complex systems with many atoms. The reaction center is described by quantum mechanics (QM). In this way, reliable predictions can be made about the breaking and formation of chemical bonds. Through the classical force field, molecular mechanics (MM) describes the environment. Although several orders of magnitude faster than QM, the bonding mode remains unchanged. The combination (QM/MM) allows accurate prediction of reaction energy with reasonable calculation time. In electrostatic embedding, the QM density is polarized by the MM charge. QM/MM is particularly suitable for the simulation of biological systems.

Figure 1. QM/MM simulations.

Overall solutions

CD ComputaBio offers many methods for treating complex systems such as molecules in solutions, proteins, polymers, molecular clusters, etc.

Implicit solvation models

SM8, SM12, SMD, COSMO, C-PCM, SS(V)PE, IEF-PCM, and CMIRS.
Intrinsically smooth discretization of the solute/continuum interface.
Poisson equation solver for anisotropic dielectric boundary conditions.

Effective fragment potential (EFP) for modeling explicit solvent with polarizable embedding

Built-in library of effective fragments and user-defined potentials
Available for DFT and wave function-based ground and excited state methods
Fragmented EFP scheme for macromolecules

Stand-alone QM/MM capabilities

Available for ground- or excited-state QM treatments
Integration with PCM models (QC/MM/PCM)
Many-body expansion for incorporating solvent at a QM level

Subtractive QM/MM Coupling

In the subtractive scheme, the QM/MM energy of the system is obtained in three steps. First, the energy of the total system, consisting of both QM and MM regions, is evaluated at the MM level. The QM energy of the isolated QM subsystem is added in the second step. Third, the MM energy of the QM subsystem is computed and subtracted.

Additive QM/MM Coupling

In additive schemes, the QM system is embedded within the larger MM system, and the potential energy for the whole system is a sum of MM energy terms.

Services items

Project name	QM/MM Simulation Service
Our services	An important advantage of QM/MM methods is their efficiency. The cost of doing classical molecular mechanics (MM) simulations in the most straightforward case scales as O(N²), where N is the number of atoms in the system. This is mainly due to electrostatic interactions term (every particle interacts with everything else).
Cycle	Depends on the time you need to simulate and the time required for the system to reach equilibrium.
Product delivery mode	The simulation results provide you with the raw data and analysis results of molecular dynamics.
Price	Inquiry

The application of the QM/MM method in the simulation and calculation of biological macromolecule systems is theoretically discussed. Practice shows that this method can improve the accuracy of the calculation results and effectively reduce the calculation cost. CD ComputaBio' QM/MM simulation service can reduce the cost of later experiments. QM/MM simulation service is a personalized and customized innovative scientific research service. Before determining the corresponding analysis plan and price, each project needs to be evaluated. If you want to know more about service prices or technical details, please feel free to contact us.