Distributed Multipoles and Energies of Flexible Molecules

Area of Science:

• Computational chemistry
• Quantum chemistry
• Molecular modeling

Background:

• Accurate calculation of molecular energies and distributed multipoles is crucial for understanding molecular behavior.
• Small molecules like amino aldehydes are fundamental building blocks in larger systems.

Purpose of the Study:

• To accurately determine energies and distributed multipoles for small molecules (Gly and Ala) using a novel interpolation method.
• To assess the method's applicability to complex molecular configurations, including those found in protein crystal structures.

Main Methods:

• Modified Shepard interpolation of ab initio data.
• Importance sampling of relevant configuration spaces.
• Interpolation of "axis free" multipoles.

Main Results:

• Accurate determination of energies and distributed multipoles up to rank two for Gly and Ala.
• Demonstrated applicability to high-dimensional configuration spaces (12D for Gly, 15D for Ala).
• Successful interpolation of "axis free" multipoles.

Conclusions:

• Modified Shepard interpolation is a robust method for accurate ab initio property determination in small molecules.
• The method is general and suitable for diverse applications like crystal structure prediction and molecular dynamics simulations.
• This approach facilitates efficient exploration of complex molecular configuration spaces.