Prerequisites

Rust features

The QSym² crate defines the following features that can be specified at compilation via cargo. Some of these features are mutually exclusive.

Linear algebra backend

There are six features defining six different ways a linear algebra backend can be configured for QSym². These are inherited from the ndarray-linalg crate. One (and only one) of these must be specified:

• openblas-static: Downloads, builds OpenBLAS, and links statically
• openblas-system: Finds and links existing OpenBLAS in the system
• netlib-static: Downloads, builds LAPACK, and links statically
• netlib-system: Finds and links existing LAPACK in the system
• intel-mkl-static: Finds and links existing static Intel MKL in the system, or downloads and links statically if not found
• intel-mkl-system: Finds and links existing shared Intel MKL in the system

If the *-static backends give rise to numerical problems, please try installing the linear algebra backends directly (either via your system's package manager or by compiling from source) and then using the corresponding *-system backends.

Interfaces

• qchem: Enables Q-Chem's HDF5 archive files to be read in and analysed
• python: Enables the Python bindings for several core functionalities

Integrals

• integrals: Enables the computation of \(n\)-centre overlap integrals and \(n\)-centre overlap integral derivatives within QSym²

Composite

• standard: Enables the openblas-static and qchem features
• full: Enables the standard and integrals features

Developmental

• sandbox: Enables experimental features that are still being actively developed

Dependencies

The installation of QSym² requires the following:

• Common:

  • curl for installing the Rust compiler
  • the Rust compiler and the cargo package manager
  • git for obtaining the source code of QSym²
  • libssl-dev (Debian/Ubuntu) or openssl-devel (Rocky/Fedora/RHEL)
  • pkg-config (Debian/Ubuntu) or pkgconfig (Rocky/Fedora/RHEL)

• Feature-specific:

Feature	Dependencies	Notes
openblas-static	make, gcc, gfortran	Builds OpenBLAS and links statically (see ndarray-linalg documentation)
openblas-system	libopenblas-dev (Debian/Ubuntu) openblas-devel (Rocky/Fedora/RHEL)	Finds and links existing OpenBLAS in the system (see ndarray-linalg documentation)
netlib-static	make, gfortran	Builds LAPACK and links statically (see ndarray-linalg documentation)
netlib-system	liblapack-dev (Debian/Ubuntu) lapack-devel (Rocky/Fedora/RHEL)	Finds and links existing LAPACK in the system (see ndarray-linalg documentation)
intel-mkl-static	pkg-config (Debian/Ubuntu) pkgconfig (Rocky/Fedora/RHEL)	Finds and links existing static Intel MKL in the system, or downloads and links statically if not found (see ndarray-linalg documentation)
intel-mkl-system	pkg-config (Debian/Ubuntu) pkgconfig (Rocky/Fedora/RHEL)	Finds and links existing shared Intel MKL in the system (see ndarray-linalg documentation)
qchem	cmake, gcc	Builds the HDF5 C library and links statically
integrals	libssl-dev (Debian/Ubuntu) openssl-devel (Rocky/Fedora/RHEL)	Installs the TLS framework required for reqwest
python	Python, which is best managed via Anaconda	Installs the Python bindings for core functionalities of QSym²