Toward quantum-chemical method development for arbitrary basis functions.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Method development

Background:

• Developing flexible computational chemistry frameworks is crucial for advancing electronic structure calculations.
• Existing software often has limitations in supporting diverse basis functions.
• Integration with external tools enhances the utility of computational chemistry packages.

Purpose of the Study:

• To design and implement a flexible quantum-chemical method development framework.
• To create a basis-function-independent self-consistent field scheme.
• To enable seamless integration with third-party packages via versatile interfaces.

Main Methods:

• Implementation of a light-weight program package named molsturm.
• Development of versatile interfaces using open standards like Python.
• Demonstration of arbitrary basis function use in coupled-cluster doubles and geometry optimization.

Main Results:

• molsturm provides a basis-function-independent self-consistent field scheme.
• The framework allows for rapid extension of computational methods and addition of new basis function types.
• Successful implementation of coupled-cluster doubles and gradient-free geometry optimization using arbitrary basis functions.

Conclusions:

• molsturm offers a flexible platform for developing and testing quantum-chemical methods.
• The basis-function independence and integration capabilities accelerate research in electronic structure calculations.
• The open-source nature of molsturm promotes wider adoption and collaboration in computational chemistry.