This project provides the stda program.

Statically linked binaries can be found at the projects release page. To build from source this project uses a make based build system and requires a version of Intel Parallel Studio 17 or newer to be compiled. To trigger the build run in the root directory

make

You will find a statically linked executable named stda. To make stda accessible export

export STDAHOME=$PWD
export PATH=$PATH:$STDAHOME

If you are not a fan of make, you can use meson as alternative, but it requires a fairly new version like 0.49 or newer for a decent Fortran support. For the default backend ninja version 1.5 or newer has to be provided.

To perform a build run:

export FC=ifort
meson setup build_intel
ninja -C build_intel

To install the stda binaries to /usr/local use (might require sudo)

ninja -C build_intel install

For a local installation (or if you want to pack a release), modify the configuration by using

meson configure build_intel --prefix=/
DESTDIR=$HOME/.local ninja -C build_intel install

The build system will generate binary files in $DESTDIR/bin (don't forget to add that to PATH if it is not the case).

For parallel usage set the threads for OMP and the MKL linear algebra backend by

export OMP_NUM_THREADS=<ncores> MKL_NUM_THREADS=<ncores>

For larger systems please adjust the stack size accordingly, otherwise stack overflows will occur. Use something along the lines of this:

ulimit -s unlimited
export OMP_STACKSIZE=4G

See the manual on the release page.

• S. Grimme, A simplified Tamm–Dancoff density functional approach for the electronic excitation spectra of very large molecules, J. Chem. Phys., 2013, 138, 244104. DOI: 10.1063/1.4811331

• C. Bannwarth, S. Grimme, A simplified time-dependent density functional theory approach for electronic ultraviolet and circular dichroism spectra of very large molecules, Comput. Theor. Chem., 2014, 1040 – 1041, 45 – 53. DOI: 10.1016/j.comptc.2014.02.023

• S. Grimme and C. Bannwarth, Ultra-fast computation of electronic spectra for large systems by tight-binding based simplified Tamm-Dancoff approximation (sTDA-xTB) J. Chem. Phys., 2016, 145, 054103. DOI: 10.1063/1.4959605

• M. de Wergifosse, C. Bannwarth, S. Grimme, A simplified spin-flip time-dependent density functional theory (sf-sTD-DFT) approach for the electronic excitation spectra of very large diradicals, J. Phys. Chem. A, 2019, 123 (27), 815–5825. DOI: 10.1021/acs.jpca.9b03176

• M. de Wergifosse, S. Grimme, Nonlinear-response properties in a simplified time-dependent density functional theory (sTD-DFT) framework: Evaluation of the first hyperpolarizability, J. Chem. Phys., 2018, 149 (2), 024108. DOI: 10.1063/1.5037665

• M. de Wergifosse, S. Grimme, Nonlinear-response properties in a simplified time-dependent density functional theory (sTD-DFT) framework: Evaluation of excited-state absorption spectra, J. Chem. Phys., 2019, 150, 094112. DOI: 10.1063/1.5080199

stda is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

stda is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See the GNU Lesser General Public License for more details.

A bug is a demonstratable problem caused by the code in this repository. Good bug reports are extremely valuable for us - thank you!

Before opening a bug report:

1. Check if the issue has already been reported.
2. Check if it still is an issue or has already been fixed? Try to reproduce it with the latest version from the master branch.
3. Isolate the problem and create a reduced test case.

A good bug report should not leave others needing to chase you up for more information. So please try to be as detailed as possible in your report, answer at least these questions:

1. Which version of stda are you using? The current version is always a subject to change, so be more specific.
2. What is your environment (your laptop, the cluster of the university)?
3. What steps will reproduce the issue? We have to reproduce the issue, so we need all the input files.
4. What would be the expected outcome?
5. What did you see instead?

All these details will help people to fix any potential bugs.