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Chemical Reactions Calculation


Chemical reactions calculation is a key factor for drug discovery. Small organic molecules play a significant role in drug discovery. In order to successfully synthesize these molecules, reaction predictions are widely employed by researchers to discover cost-effective, environmentally green, and the most efficient routes to produce drug candidates on a large scale. Without hesitation, chemical reactions calculation has become a powerful tool available to help chemists to predict reactions, design synthesis routes, and elucidate mechanisms. Alfa Chemistry is committed to providing comprehensive and accurate chemical reactions calculation for chemical researchers. The questions of the greatest concern in chemical reactions calculation are forward reaction prediction, retrosynthetic analysis, and reaction mechanism elucidation. We have various problem-solving methods, on account of a wealth of professional experience.

Our Services

To make it easier and better for researchers, Alfa Chemistry provides practical chemical reactions calculation in a competitive fashion. We have prepared the most convenient services for you. Our services involve reactions, catalysis, dynamics, thermodynamics and other calculation, the services following are available for you.

Catalysis and reaction simulation is the state-of-the-art approach in the application of quantum chemistry. Our scientists are capable of performing various mechanism calculation including the calculation of enzyme catalysis, chemical catalysis, electrocatalysis, photocatalysis to elucidate reaction mechanisms and origins of selectivity. We are committed to providing fast and high-quality reaction mechanism calculation services, helping you to better understand the reaction results and mechanisms.

At Alfa Chemistry, we have created a fully automated system that will rapidly and efficiently select potential synthetic routes to produce the desired molecule. Combined with the advanced knowledge of machine learning, cheminformatics, and computational chemistry, our computational synthesis route design platform for reaction pathway identification, scoring, and selection can also guide scale-up and process optimization.

Schematic drawing of hybrid DFT.

As a powerful tool for computational study of chemical reactions, DFT method reproduces well electronic structure in transition metal compounds. In addition, it expands the simulation of molecular size and complexity. At Alfa Chemistry, DFT calculations of heterogeneous reactions on catalyst surfaces can help us to study the reactivity and mechanisms. Our DFT calculation methods can also allow for in silico screening and design of catalysts.

Examination of possible reaction paths is widely used in chemical mechanism prediction and kinetic research. We use first-principles thermodynamic calculations to describe all the possible metastable paths for reactant mixtures, and find the minimum free energy path among all the possible paths. Our scientists have rich experience in studying diverse possible reaction paths as well as examining the rationality of paths.

Advances in the increased performance of computing resources enable the automated high-throughput quantum chemical analysis of materials structure libraries containing thousands of structures. Nowadays, high throughput quantum chemistry is of great importance in drug discovery. At Alfa Chemistry, we apply the high throughput quantum mechanics-based reaction screening tool to quickly and systematically measure reactivity, and design and screen the most effective molecules.

QM/MM simulation is the combination of quantum mechanical and molecular mechanical, which has been applied to study various reactions, especially the biochemical macromolecules reaction. The basic theory of QM/MM simulation is to divide a large molecular system into a series of small molecular fragments, thereby reducing the computational cost. Our QM/MM simulation teams can study the overall properties of macromolecular systems through building quantum chemistry models. We can also explore the relationship between chemical reaction and non-reactive energy changes using QM/MM simulation methods.

Besides the above-mentioned services, Alfa Chemistry also offers you,

Ab initio quantum chemistry is a calculation method of the whole integral of the molecule using different physical quantity and atomic coefficient. Our teams enable to apply Ab initio methods to conduct the high-quality calculation of small molecular systems, medium molecular systems, and large molecular systems. Our Ab initio calculation methods can be used to predict the molecular property and materials property, investigate the catalytic reactions and other biomedical research.

Thermodynamic properties of chemical reactions play important roles in many fields such as environmental protection, materials science, and life science. Alfa Chemistry offer calculation of thermodynamic data for individual chemical reactions including predicting the reaction limit, reaction direction, and energy change. Our computational experts have designed multiple complex algorithms to complete the calculation of characteristic thermodynamic data.

Chemical process simulation is the representation of a chemical process through building a mathematical model that involves the calculation of mass and energy balances. Chemical process simulation is often coupled with phase equilibrium, transport, and chemical kinetics equations. Our chemical process simulation methods can be applied in both steady-state process simulation and dynamic-state process simulation.

Computational fluid dynamics is a branch of computer aided engineering, and CFD uses numerical methods to simulate fluid motion and heat transfer. We apply CFD-based computational fluid dynamics technologies to simulate and analyze complex problems involving fluid-fluid, fluid-solid, or fluid-gas interactions during chemical reactions. At Alfa Chemistry, Euler-Lagrangian method and Euler-Euler method are commonly applied to calculate multiphase flow values.

In thermodynamics, enthalpy is used to characterize the state parameter of the system. Calculation of enthalpy changes is to calculate the heat energy change when the temperature of a pure substance is changed. Alfa Chemistry supports various enthalpy formula and reaction scheme method to calculate changes in enthalpy. In addition, we are capable of carrying out the calculation of standard molar enthalpy of formation, calculation of standard molar reaction enthalpy for conformational transformation, and calculation of the standard molar reaction enthalpy change.

For a chemical reaction, the equilibrium constant is defined as the ratio between the amount of reactant and the amount of product. The equilibrium constant is used to quantify the equilibrium state and determine chemical behaviour. We use computational density functional theory interaction energies to calculate the equilibrium constants, helping to judge the progress of the reaction and estimate the possibility of the reaction.

The transition dipole moment or transition moment, usually refers to a transition between an initial state a and a final state b, is the electric dipole moment associated with the transition between the two states. Transition dipole moment calculation is an important part of excited state calculation. We calculate the transition dipole moment between the excited states and use the obtained value to calculate the (hyper) polarizability, and calculate the absorption spectrum from the excited state to the excited state.

Alfa Chemistry supports the application of ultrafast pulsed X-ray free-electron lasers and mega-electron-volt radio frequency (RF) electron guns to determine transient molecular structures in excited states. Our groups refine the structure of molecule by adjusting it until the structure obtained by simulation is consistent with the structure of the experimental model. Moreover, we are capable of calculating the excited state of the optimized structure.

Our scientists can use various formulae to conduct a rapid calculation of number of π -bonds. We can easily predict nature of bonds in alkyne system in a very simple and metabolic way by using these methods. Combined with our knowledge in computational quantum chemistry, we discuss the nature of the interaction between atoms in complexes with π bonds. At Alfa Chemistry, various algorithms are used to study the configuration, frequency, interaction energy, etc. of the complex.

Hydrogen bond and halogen bond are two common weak interactions between molecules. We use Gaussian software to design a series of algorithms to calculate the bond energies of hydrogen bonds and halogen bonds. Aiming to obtain accurate values of hydrogen bonds and halogen bonds, we also conduct the optimization and validation. In addition, we can also obtain the potential energy surfaces of the hydrogen bond and halogen bond system through the quantitative calculations, and study the halogen bond and hydrogen bond respectively.

Rate-limiting reaction is the slowest reaction in a series of reactions and has the highest activation energy of all reactions in the series. Scientists use the rate-limiting reaction to calculate the rate law of the overall reaction. Identification of the rate-limiting step in a metabolic pathway plays an essential role in metabolic engineering for enhancing pathway flow. We have introduced a novel, efficient Monte Carlo procedure to simulate all possible meaningful states of a metabolic network and to compute the corresponding values of the kinetic constants of the individual reaction steps.

Molecular simulation of chemical reactions at surfaces refers to modeling surface reactions and study the dynamics of chemical reactions on simple surfaces. At Alfa Chemistry, we use multiple advanced software to realize molecular dynamics simulation of chemical reactions on the surface of materials. Our groups apply molecular mechanics methods based on force fields to study the interactions and reactions between biological macromolecules.

Salt bridges affect the function, physical and chemical properties of proteins, such as enzyme catalysis, protein-protein interactions, protein-DNA/RNA interactions, molecular recognition, etc. We use molecular dynamics simulation methods to calculate the change of the free energy of salt bridges with temperature. In addition to the salt bridge between amino acids and amino acids, our teams can also simulate and calculate the salt bridge between small molecules and amino acids.

The Van der Waals Interaction plays an important role in the determination of structures of biomolecular chains that define their biological activities. This molecular interaction affects various properties of molecules and solids, such as attice constants, cohesive or sublimation energies, and physisorption. At Alfa Chemistry, we use molecular simulation methods of force field based on Newtonian mechanics to describe the Van der Waals Interaction.

In quantum mechanics, the wave function refers to the mathematical function used to describe the state of the particle system. The function determines all the properties of the particle system. Therefore, determination of an appropriate wave function for the particle system is required to describe the properties of the system accurately. Wavefunction stability determination refers to the calculation to determine whether the wave function is the most stable, that is, whether the energy of the wave function is the lowest.

Alfa Chemistry is committed to providing comprehensive and accurate chemical reaction high-precision computing services for researchers in the field of chemistry. The most important problems in the high-precision calculation of chemical reactions are the calculation of transition states of chemical reactions and the coordinates of intrinsic reactions.

We use molecular mechanics, quantum chemistry and other methods to provide customers with comprehensive and accurate transition state calculations for chemical reactions. We use the calculation software "Gaussian09/16" to provide high-quality and fast service, requiring customers to provide the structure and force constants of the transition state.

Our Advantages

  • Flexible and advanced computational methods
  • Personalized and customized innovative scientific research services
  • Cost-efficient and time-saving

Chemical reactions calculation provides an effective way to explore the nature of chemical reactions and predict the possible synthesis planning. Our chemical reactions calculation services remarkably reduce the cost, promote further experiments, and enhance the understanding of catalytic reactions for customers worldwide. Our personalized and all-around services will satisfy your innovative study demands. If you are interested in our services, please don't hesitate to contact us. We are glad to cooperate with you and witness your success!


  • Engkvist, O.; et al. Computational prediction of chemical reactions: current status and outlook [J]. Drug Discov. Today 2018, 23(6): 1203-1218.
  • Onishi, T. Quantum computational chemistry: Modelling and calculation for functional materials [M]. Springer. 2018: 83-84.

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