Implementations in CP2k

CP2k is a very powerful program package for performing electron structure calculations of periodic bulk phase systems.

CP2k Program Package

During my scientific guest visit at the University of Zurich in the group of Prof. Jürg Hutter, I have implemented several new features into CP2k:

Voronoi Integration

The Voronoi integration, which we have developed in 2015, is a technique to compute molecular electromagnetic properties such as the electric dipole moment and the electric quadrupole tensor via integration of the total electron density within Voronoi cells. These properties, in turn, are required for computing vibrational spectra from AIMD simulations. I have implemented the Voronoi integration into CP2k, it is available since release 8.1 (December 2020).
See the &DFT/&PRINT/&VORONOI manual section.

bqb Format

In 2018, we have developed a lossless compression algorithm for volumetric data trajectories, and a corresponding new file format, which is the bqb format. I have implemented support for writing the total electron density in bqb format into CP2k, it is available since release 8.1 (December 2020).
See the &DFT/&PRINT/&E_DENSITY_BQB manual section.

Note: If you compile CP2k 8.1 or newer via the Toolchain script, these features will automatically be included by default, and the library will automatically be downloaded and compiled in the process. If you prefer not to use the Toolchain, you need to download and compile the libvori source code from here.

— Related Publications —

21 of my publications are based on CP2k calculations:

45E. Roos, M. Brehm:
"A Force Field for Bio-Polymers in Ionic Liquids (BILFF) – Part 1: [EMIm][OAc] / Water Mixtures"
Phys. Chem. Chem. Phys. 2021, 23, 1242–1253.     (DOI 10.1039/D0CP04537C ) ⭳Bib
43M. Weiß, M. Brehm:
"Exploring Free Energy Profiles of Enantioselective Organocatalytic Aldol Reactions under Full Solvent Influence"
Molecules 2020, 25 (24), 5861.     (DOI 10.3390/molecules25245861 ) ⭳Bib
Open Access
37L. Scarbath-Evers, R. Hammer, D. Golze, M. Brehm, D. Sebastiani, W. Widdra:
"From Flat to Tilted: Gradual Interfaces in Organic Thin Film Growth"
Nanoscale 2020, 12, 3834–3845.     (2 citations, DOI 10.1039/C9NR06592J ) ⭳Bib
Open Access
36M. Brehm, M. Thomas:
"Computing Bulk Phase Resonance Raman Spectra from ab initio Molecular Dynamics and Real-Time TDDFT"
J. Chem. Theory Comput. 2019, 15 (7), 3901–3905.     (3 citations, DOI 10.1021/acs.jctc.9b00512 ) ⭳Bib
31M. Brehm, D. Sebastiani:
"Simulating Structure and Dynamics in Small Droplets of 1-Ethyl-3-Methylimidazolium Acetate"
J. Chem. Phys. 2018, 148, 193802.     (12 citations, DOI 10.1063/1.5010342 ) ⭳Bib
26M. Brehm, M. Thomas:
"Computing Bulk Phase Raman Optical Activity Spectra from ab initio Molecular Dynamics Simulations"
J. Phys. Chem. Lett. 2017, 8 (14), 3409–3414.     (10 citations, DOI 10.1021/acs.jpclett.7b01616 ) ⭳Bib
23M. Thomas, M. Brehm, B. Kirchner:
"Voronoi Dipole Moments for the Simulation of Bulk Phase Vibrational Spectra"
Phys. Chem. Chem. Phys. 2015, 17, 3207–3213.     (49 citations, DOI 10.1039/C4CP05272B ) ⭳Bib
20A. Stark, M. Brehm, M. Brüssel, S. B. C. Lehmann, A. S. Pensado, M. Schöppke, B. Kirchner:
"A Theoretical and Experimental Chemist’s Joint View on Hydrogen Bonding in Ionic Liquids and Their Binary Mixtures"
Top. Curr. Chem. 2014, 351, 149–187.     (19 citations, DOI 10.1007/128_2013_485 ) ⭳Bib
19M. Thomas, M. Brehm, O. Hollóczki, Z. Kelemen, L. Nyulászi, T. Pasinszki, B. Kirchner:
"Simulating the Vibrational Spectra of Ionic Liquid Systems: 1-Ethyl-3-Methylimidazolium Acetate and its Mixtures"
J. Chem. Phys. 2014, 141, 024510.     (46 citations, DOI 10.1063/1.4887082 ) ⭳Bib
17S. Zahn, M. Brehm, M. Brüssel, O. Hollóczki, M. Kohagen, S. B. C. Lehmann, F. Malberg, A. S. Pensado, M. Schöppke, H. Weber, B. Kirchner:
"Understanding Ionic Liquids from Theoretical Methods"
J. Mol. Liq. 2014, 192, 71–76.     (47 citations, DOI 10.1016/j.molliq.2013.08.015 ) ⭳Bib
16M. Thomas, M. Brehm, O. Hollóczki, B. Kirchner:
"How Can a Carbene be Active in an Ionic Liquid?"
Chem. Eur. J 2014, 20 (6), 1622–1629.     (42 citations, DOI 10.1002/chem.201303329 ) ⭳Bib
15F. Malberg, M. Brehm, O. Hollóczki, A. S. Pensado, B. Kirchner:
"Understanding the Evaporation of Ionic Liquids using the Example of 1-Ethyl-3-Methylimidazolium Ethylsulfate"
Phys. Chem. Chem. Phys. 2013, 15, 18424–18436.     (21 citations, DOI 10.1039/C3CP52966E ) ⭳Bib
14M. Thomas, M. Brehm, R. Fligg, P. Vöhringer, B. Kirchner:
"Computing Vibrational Spectra from ab initio Molecular Dynamics"
Phys. Chem. Chem. Phys. 2013, 15, 6608–6622.     (220 citations, DOI 10.1039/C3CP44302G ) ⭳Bib
Cover Art
13M. Brehm, H. Weber, A. S. Pensado, A. Stark, B. Kirchner:
"Liquid Structure and Cluster Formation in Ionic Liquid/Water Mixtures – An Extensive ab initio Molecular Dynamics Study on 1-Ethyl-3-Methylimidazolium Acetate/Water Mixtures – Part 2"
Z. Phys. Chem. 2013, 227, 177–203.     (30 citations, DOI 10.1524/zpch.2012.0327 ) ⭳Bib
12O. Hollóczki, D. S. Firaha, J. Friedrich, M. Brehm, R. Cybik, M. Wild, A. Stark, B. Kirchner:
"Carbene Formation in Ionic Liquids: Spontaneous, Induced, or Prohibited?"
J. Phys. Chem. B 2013, 117 (19), 5898–5907.     (88 citations, DOI 10.1021/jp4004399 ) ⭳Bib
10M. Brüssel, M. Brehm, A. S. Pensado, F. Malberg, M. Ramzan, A. Stark, B. Kirchner:
"On the Ideality of Binary Mixtures of Ionic Liquids"
Phys. Chem. Chem. Phys. 2012, 14, 13204–13215.     (73 citations, DOI 10.1039/C2CP41926B ) ⭳Bib
9K. Wendler, M. Brehm, F. Malberg, B. Kirchner, L. Delle Site:
"Short Time Dynamics of Ionic Liquids in AIMD-Based Power Spectra"
J. Chem. Theory Comput. 2012, 8 (5), 1570–1579.     (49 citations, DOI 10.1021/ct300152t ) ⭳Bib
8M. Brehm, H. Weber, A. S. Pensado, A. Stark, B. Kirchner:
"Proton Transfer and Polarity Changes in Ionic Liquid–Water Mixtures: A Perspective on Hydrogen Bonds from ab initio Molecular Dynamics at the Example of 1-Ethyl-3-Methylimidazolium Acetate–Water Mixtures—Part 1"
Phys. Chem. Chem. Phys. 2012, 14, 5030–5044.     (118 citations, DOI 10.1039/C2CP23983C ) ⭳Bib
7A. S. Pensado, M. Brehm, J. Thar, A. P. Seitsonen, B. Kirchner:
"Effect of Dispersion on the Structure and Dynamics of the Ionic Liquid 1-Ethyl-3-Methylimidazolium Thiocyanate"
ChemPhysChem 2012, 13 (7), 1845–1853.     (69 citations, DOI 10.1002/cphc.201100917 ) ⭳Bib
4M. Brüssel, M. Brehm, T. Voigt, B. Kirchner:
"Ab initio Molecular Dynamics Simulations of a Binary System of Ionic Liquids"
Phys. Chem. Chem. Phys. 2011, 13, 13617–13620.     (58 citations, DOI 10.1039/C1CP21550G ) ⭳Bib
1J. Thar, M. Brehm, A. P. Seitsonen, B. Kirchner:
"Unexpected Hydrogen Bond Dynamics in Imidazolium-Based Ionic Liquids"
J. Phys. Chem. B 2009, 113 (46), 15129–15132.     (97 citations, DOI 10.1021/jp908110j ) ⭳Bib