This project provides xtb4stda, a program to calculate the ground state with sTDA-xTB to be used in further stda calculations. This fork provides functionality for MACOS.

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 (also requires ruby for some hacky scripts). To trigger the build run in the root directory

make

You will find a statically linked executable in xtb4stda. To make xtb4stda accessible export

export XTB4STDAHOME=$PWD
export PATH=$PATH:$XTB4STDAHOME

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

To make adjustments to the build system check the directory MAKE/.

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 (with GCC, run export FC=ifort for Intel builds)

meson setup build_gcc
ninja -C build_gcc

This also allows to install the program locally by running

[sudo] ninja -C build_gcc install

Which will default to an installation in /usr/local and should automatically include xtb4stda in your systems PATH variable. The environment variable to set is than usually only

export XTB4STDAHOME=/usr/local/share/xtb4stda

The xtb4stda binary will read the geometry from its first command line argument and the input is assumed to be either a Turbomole coordinate data group or a xyz-file. The extension of the file is not used to distinguish files.

xtb4stda coord > gs.stda-xtb.out

After the run you will find a wfn.xtb file in the directory which can be used with the stda program.

• S. Grimme and C. Bannwarth, J. Chem. Phys., 2016, 145, 054103. DOI: 10.1063/1.4959605

xtb4stda 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.

xtb4stda 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 xtb4stda 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.

For large systems with more than 33000 basis functions an integer overflow in the linear algebra backend will occur. To amend this issue the integer precision range must be increased from 32 bits to 64 bits by recompiling the program. Adjust the make build by changing -lmkl_intel_lp64 to -lmkl_intel_il64 in MAKE/Makerules or when using the meson backend by adding -Dinterface=64 in the configuration step. Note that this option is currently only supported with the MKL backend.