12019-05-29 2Susi Lehtola 3 4 5** Prerequisites ** 6 7To compile ERKALE you need 8 9* CMake ( http://cmake.org ), at least version 2.6 10* The GNU Scientific Library ( http://www.gnu.org/s/gsl/ ), at least version 1.4 11* HDF5 ( http://www.hdfgroup.org/HDF5/ ), at least version 1.8 12* libint ( http://sourceforge.net/p/libint/home ) 13* libxc ( http://www.tddft.org/programs/octopus/wiki/index.php/Libxc ) 14* Armadillo ( http://arma.sourceforge.net/ ) 15 16Naturally, you also need a decent LAPACK library installed. The use of 17an optimized library such as ATLAS, Intel MKL or AMD ACML is recommended. 18 19To compile, please use the attached script compile.sh and modify it to 20suit your needs. Note that by default the build system creates an 21OpenMP parallellized version of ERKALE. The parallellization is quite 22trivial, but should still give about 80% of speedup. If you don't want 23ERKALE to be parallellized, give the argument "-DUSE_OPENMP=OFF" to 24cmake. 25 26If you wish to create the developer documentation, you need a working 27installation of doxygen and LaTeX. The documentation can be created by 28running 29 $ doxygen 30 31** Usage ** 32 33ERKALE is used in the following manner 34 $ erkale input 35 36Here "input" is a file, that contains at least the directive "Method", 37which can be either "HF" for a Hartree-Fock calculation or a 38specification of a DFT exchange-correlation functional. For example 39 Method gga_x_pbe-gga_c_pbe 40will run a calculation with PBE exchange and PBE correlation, and 41 Method hyb_gga_xc_b3lyp 42will run a B3LYP calculation. 43 44Please consult the list of supported functionals for more choices. 45 46Upon startup, ERKALE will print out the current settings, along with 47valid keywords. 48 49** Example ** 50 51Here is an example input file: 52 Method HF 53 Basis aug-cc-pVTZ 54 System ethanol.xyz 55 SaveChk ethanol-hf.chk 56 LoadChk ethanol-lda.chk 57 Cholesky false 58 Direct true 59 60The first line specifies that a Hartree-Fock calculation is requested. 61 62The second line specifies that the aug-cc-pVTZ basis is to be used in 63the calculation. ERKALE searches for the basis set in the following order: 64 1. A basis set library location specified by the environmental 65 variable ERKALE_LIBRARY. 66 2. In the current directory. 67 3. In the system wide basis set library repository, which is by 68 default /usr/share/erkale/basis. The value can be changed via a 69 compile-time option (add to cmake flags), e.g., 70 -DERKALE_SYSTEM_LIBRARY=/usr/local/share/erkale/basis. 71The .gbs extension is automatically added, if necessary. 72 73The third line states that the atoms in the system are to be read 74from the file "ethanol.xyz". The file must be in xyz format, for 75example: 76 3 77 B3LYP aug-cc-pVTZ optimized water molecule 78 O 0.000000 0.117030 0.000000 79 H 0.763404 -0.468123 0.000000 80 H -0.763404 -0.468115 0.000000 81 82The fourth line states that the results of the calculation should be 83saved to the file erkale-hf.chk. 84 85The fifth line asks that the calculation be initialized with the 86wavefunction from the file erkale-lda.chk. The idea behind this is to 87speed up the calculation: by default a core guess is used, which 88completely ignores electron-electron repulsion. By initializing the 89calculation with a more sane starting guess (density-fitted 90density-functional theory calculation), the necessary number of 91(costly) Hartree-Fock iterations can be brought down. 92 93The sixth line turns off the use of the Cholesky decomposition for 94two-electron integrals, which is used by default. 95 96The seventh line states that two-electron (and density-fitting) 97integrals should be computed on the fly. By default, the integrals are 98tabled in memory. 99 100** Contact information ** 101 102Dr Susi Lehtola 103Department of Chemistry 104University of Helsinki 105P. O. Box 55 106FI-00014 UNIVERSITY OF HELSINKI 107FINLAND 108 109susi (dot) lehtola (at) alumni (dot) helsinki (dot) fi 110