Commandline Usage¶
For xtb
we usually enjoy to build our workflows via commandline,
so most tasks can be performed without ever writing any kind of input file
(except for the geometry input, of course).
The man page can be found here.
Note
If you need more control you should resort to the Detailed Input file.
Contents
Runtypes¶
The most basic flags used in xtb
are the runtypes. We have a bunch of
them, but many of the elaborate composite runtypes are constructed from
four basic runtypes: singlepoint (SP), geometry optimization (ANCopt),
frequency calculation (Hessian) and molecular dynamics (MD).
Every calculation performs the basic setup and at some (resonable) point
a property calculation.
- Singlepoint
flag: --scc
description: just self-consistent charge (SCC) calculation. See Singlepoint Calculations for details. queue: setup, SP, properties - Gradient
flag: --grad
description: self-consistent charge (SCC) calculation, afterwards energy and gradient will be printed in a Turbomole readable format queue: setup, SP, properties - Vertical IP
flag: --vip
description: vertical ionisation potential (IP), calculates SCC on input structure and than removes an electron to perform another SCC calculation. queue: setup, SP, SP, properties - Vertical EA
flag: --vea
description: vertical electron affinity (EA), calculates SCC on input structure and than adds an electron to perform another SCC calculation. queue: setup, SP, SP, properties - Vertical IP and EA
flag: --vipea
description: both IP and EA are calculate by removing and adding an electron, respectively. queue: setup, SP, SP, SP, properties - Global Electrophilicity Index
flag: --vomega
description: global electrophilicity index from vertical IP and EA. queue: setup, SP, SP, SP, properties - Fukui Indices
flag: --vfukui
description: calculates Mulliken partial charges from the neutral, positive and negatively charged structure and calculates Fukui indices. queue: setup, SP, SP, SP, properties - Electrostatic Potential
flag: --esp
description: calculate electrostatic potential on VdW-grid queue: setup, SP, properties (with ESP calculation) - STM picture
flag: --stm
description: simulate a STM measurement (molecule should be aligned to xy-plane) queue: setup, SP, properties (with STM calculation) - Geometry optimization
flag: --opt
description: approximate normal coordinate optimization, performs an initial singlepoint calculation and a final singlepoint calculation on the optimized structure. See Geometry Optimization for details. queue: setup, SP, ANCopt, SP, properties - Minimum Hopping
flag: --metaopt
description: try to find conformers by geometry optimization, for each minimum located a bias potential is generated to push the optimizer to another local minimum. queue: setup, SP, ANCopt, SP, properties, ANCopt, … - Guided Path Finder
flag: --path [file]
description: apply a bias potential between the input and final geometry (from file) and force the geometry optimizer to generate a path between the two structures. queue: setup, SP, properties, ANCopt, … - Modefollowing
flag: --modef mode
description: follow mode
which specifies the nth eigenmode from a previously done frequency calculation.queue: setup, SP, properties, ANCopt, … - Frequency calculation
flag: --[o]hess
description: second derivative calculation, see Calculation of Vibrational Frequencies queue: setup, SP, [ANCopt, SP,] SP, Hessian, properties - Molecular dynamics
flag: --[o]md
description: molecular dynamics simulation, see Molecular Dyamics Simulations for details queue: setup, SP, [ANCopt, SP,] properties, MD - Metadynamics
flag: --metadyn [snapshots]
description: activates metadynamics simulation on start geometry, where snapshots
is the number of structures from the trajectory should be used in the biasing potential. See Meta-Dynamics Simulations for details.queue: setup, SP, properties, MD - Simulated annealing
flag: --siman
description: performs a number of simulated annealing steps on the input coordinates and tries to find a conformer ensemble. We recommend the CREST workflow (see Introduction to CREST) instead of this runtyp since it is faster and more reliable in finding the lowest conformer. This runtyp has been deprecated and removed in version 6.2! queue: setup, SP, properties, MD, ANCopt, …
Options¶
-c, --chrg INT | specify molecular charge as INT, overrides .CHRG file and xcontrol option |
-u, --uhf INT | specify Nalpha-Nbeta as INT, overrides .UHF file and xcontrol option |
--gfn INT | specify parametrisation of GFN-xTB (default = 2) |
--etemp REAL | electronic temperature (default = 300K) |
-a, --acc REAL | accuracy for SCC calculation, lower is better (default = 1.0) |
--vparam FILE | Parameter file for vTB calculation |
- –alpb SOLVENT [reference]
- analytical linearized Poisson-Boltzmann (ALPB) model, available solvents are acetone, acetonitrile, aniline, benzaldehyde, benzene, ch2cl2, chcl3, cs2, dioxane, dmf, dmso, ether, ethylacetate, furane, hexandecane, hexane, methanol, nitromethane, octanol, woctanol, phenol, toluene, thf, water. The solvent input is not case-sensitive. The Gsolv reference state can be chosen as reference or bar1M (default).
- -g, –gbsa SOLVENT [reference]
- generalized born (GB) model with solvent accessable surface (SASA) model, available solvents are acetone, acetonitrile, benzene (only GFN1-xTB), CH2Cl2, CHCl3, CS2, DMF (only GFN2-xTB), DMSO, ether, H2O, methanol, n-hexane (only GFN2-xTB), THF and toluene. The solvent input is not case-sensitive. The Gsolv reference state can be chosen as reference or bar1M (default).
--cma | shifts molecule to center of mass and transforms cartesian coordinates
into the coordinate system of the principle axis (not affected by
isotopes -file). |
--pop | requests printout of Mulliken population analysis (done by default) |
--molden | requests printout of molden file |
--dipole | requests dipole printout (done by default) |
--wbo | requests Wiberg bond order printout (done by default) |
--lmo | requests localization of orbitals |
--fod | requests FOD calculation |
-I, --input FILE | |
use FILE as input source for xcontrol(7) instructions | |
--namespace STRING | |
give this xtb(1) run a namespace. All files, even temporary
ones, will be named according to STRING. | |
--copy, --nocopy | |
copies the xcontrol file at startup (default = false) | |
--restart, --norestart | |
restarts calculation from xtbrestart (default = true) | |
-P, --parallel INT | |
number of parallel processes | |
--define | performs automatic check of input and terminate |
--citation | print citation and terminate |
--license | print license and terminate |
-v, --verbose | be more verbose (not supported in every unit) |
-s, --silent | clutter the screen less (not supported in every unit) |
--strict | turns all warnings into hard errors |
-h, --help | show help page |