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High-Precision Computing


For the research and forecasting of physical processes driven by chemical kinetics, detailed reaction mechanisms are useful tools. Chemical kinetics has transitioned from a post-predictive modeling technique to a predictive modeling approach in recent decades. This change has been prompted by improvements in computing capacity, which have made it possible to forecast many kinetic parameters without relying on experimental data by, for instance, utilizing ab initio simulation computations. Today's large-scale scientific computing environment is a fundamental component of which high-precision arithmetic tools are a key component.

Alfa Chemistry is committed to offering thorough and precise chemical reaction high-precision computing services to researchers in the field of chemistry. The most important concerns in chemical reaction high-precision computing are chemical reaction transition state calculations and intrinsic reaction coordinates.

High-Precision Computing

Our Services

Molecular conformational changes and chemical reactions often involve transition states, that is, the motion of the process on the potential energy surface often passes through a point that satisfies the above conditions. Currently, the most effective tool for predicting transition states is computational chemistry. Alfa Chemistry uses molecular mechanics, quantum chemistry and other methods to provide customers with comprehensive and accurate transition state calculations of chemical reactions. These quantum chemical transition state calculation methods and molecular mechanics calculation of transition state methods include but are not limited to:

  • Quasi-Newton Raphson (NR) Method
  • Gradient Extramal Method (GE2JJH Method, GE2SR Method)
  • Trust-Region Image Minimization (TRIM) Method
  • Image Potential in Trinsic Reaction Coordinate (IPIRC) Method
  • Constrained Optimization (CONOPT) Method
  • Line-Then-Olane (LTP) Method
  • Rigid Transition State Model
  • Flexible Transition State Model
  • Constructed Potential Function Method

Intrinsic Reaction Coordinates (IRCs) provide a unique link from a given transition structure to local minima on the reactant and product sides, describing the optimal trajectories of chemical processes for structural changes regardless of thermal motion factors.

Alfa Chemistry is committed to providing chemical researchers with comprehensive and accurate chemical reaction IRC calculation services. We use the calculation software "Gaussian09/16" to provide a high-quality and fast service, which requires customers to provide the structure and force constants of the transition state. IRC calculations are the most conclusive method for confirming that the correct transition state has been found, and are often used in quantum chemical research and prediction of chemical reaction pathways.

Fluvoxamine trans-to-cis structure intrinsic reaction coordinates IRC and its total energy.Fig 1. Fluvoxamine trans-to-cis structure intrinsic reaction coordinates IRC and its total energy. (Odai K, et al. 2020)

Our Advantages

  • We have a wide range of flexible and advanced computational methods.
  • We provide personalized and customized innovative research services.
  • Our chemical reaction calculation services are cost-effective and time-saving.

High-precision calculation services for chemical reactions provide an efficient way to explore the nature of chemical reactions. Our personalized, full-service customization significantly reduces costs and facilitates further experiments that will meet the innovative learning needs of our clients. If you are interested in our services, please feel free to contact us. We would be happy to work with you and see you through to success!


  • Odai K, et al. (2020). "Quantum Chemical Calculation of Intrinsic Reaction Coordinates from Trans to Cis Structure of Fluvoxamine." Computational and Theoretical Chemistry. 1192: 113051.

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