Matrix polynomial

Physics

Potential energy surface

Mathematical analysis

Invariant polynomial

Computational chemistry

Chemistry

Invariant (physics)

Materials science

Acetamide

Molecule

Mathematics

Quantum mechanics

Potential energy

Astrobiology

Polynomial

The Journal of Chemical Physics

We describe and apply a method to extend permutationally invariant polynomial (PIP) potential energy surface (PES) fitting to molecules with more than 10 atoms. The method creates a compact basis of PIPs as the union of PIPs obtained from fragments of the molecule. An application is reported for trans-N-methyl acetamide, where B3LYP/cc-pVDZ electronic energies and gradients are used to develop a full-dimensional potential for this prototype peptide molecule. The performance of several fragmented bases is verified against a benchmark PES using all (66) Morse variables. The method appears feasible for much larger molecules.

A fragmented, permutationally invariant polynomial approach for potential energy surfaces of large molecules: Application to <i>N</i>-methyl acetamide

A fragmented, permutationally invariant polynomial approach for potential energy surfaces of large molecules: Application to N-methyl acetamide