1. Read Checkpoint File Gaussian Pdf
2. Read Checkpoint File Gaussian Software
3. Read Checkpoint File Gaussian Online
4. Read Checkpoint File Gaussian Free
5. Read Checkpoint File Gaussian Tool

The checkpoint file name. See Reading gaussian checkpoint files if you don't understand. Specify the type of density matrix you want; in the above it is the rohf type. You don't need to do an scf calculation, just specify the kind of density matrix in scfdata= Change the type of plot from electricpotential to what you want. May 07, 2014 You cannot open a chk file. You first need to format it into an fchk file, then you can edit that one with any text editor of your choice. Use the formchk utility from Gaussian to do so. I hope this helps! Aug 19, 2015 It extracts the title and route sections from a checkpoint file. The command usage is. Chkchk filename. Where filename.chk is the name of a checkpoint file in the current directory. Chkmove is another utility provided with Gaussian. It is used to move checkpoint files between machines of different architecture.

Gaussian input files have the file extension .gjf or .com.Jobs will read in data from a checkpoint (.chk) file, or write to new file.Logfiles (.log) contain all the information about the job, andwhether it failed or ran successfully.

Read Checkpoint File Gaussian Pdf

Water Example

Here is what a basic input for water would look like.

This input, with explanatory comments marked with ### is:

Calculate → Gaussian Calculation Set-Up

Job Type

1. Energy: Calculates the energy and wavefunction at a single, fixedgeometry
2. Optimization: Attempts to find the structure’s minimum energyconfiguration
3. Frequency: Gives thermochemical properties of the structure
4. Opt + Freq: Performs both optimization and frequency
5. IRC: Asks to follow a reaction path by integrating the intrinsic reactioncoordinate
6. Scan: Scans the potential energy surface by performing single-pointenergy calculations
7. Stability: Checks stability by determining if imaginary (negative)frequencies exist (Yes? That’s bad, unless a transition state.)
8. NMR: Predicts NMR shielding tensors

Method

• Method: the “school of thought” for the wavefunction
• Basis set: contains all the functions that represent the wavefunction
  • Higher-order basis sets are often more accurate, but at a higher computational/time cost
  • Diffuse functions (ex: +, ++) describe very electronegative atoms
  • Polarization functions (ex: d, p) allow for angular flexibility (i.e., reduces the strain from lots of electrons)
• Charge: overall charge of the structure
• Spin: pairing of the electrons
  • Singlet: All electrons paired
  • Multiplicity = Number of unpaired electrons + 1

Read Checkpoint File Gaussian Software

Solvation

Read Checkpoint File Gaussian Online

• Implicit: Solvent is a polarizable continuum with dielectric constant,ε
  • Not terribly costly
  • Cannot model specific interactions, like hydrogen bonds
  • Magician waving a wand 0019 there’s some magic happening, but you can’t see it
• Explicit: Want a solvent? Build it in. Put it there.
  • Expensive…
  • Can get stuff like hydrogen bonds
  • As magician’s apprentice, you see all the things going into the “magic”

Ever wonder what’s in some of the numerous checkpoint files you have accumulated or which checkpoint file of several is the one you want? The chkchk utility will show you information about the job that created a checkpoint file. The first two extracted items in its output are the title and route sections from the job:

The lines following the title and route sections indicate what data is present in the checkpoint file. In this case, the data from the various steps of the optimization and the force constants from the frequency calculation are present, as well as the results of the latter. These force constants can be used for a later optimization with a more accurate model chemistry (e.g., TD in this case).

Read Checkpoint File Gaussian Free

This example demonstrates the importance of using the title section to specify details about the job. The route section alone may be enough for you to identify the contents of a particular checkpoint file, but putting full details in the title section makes it even easier.

You can also retrieve the geometry stored in the checkpoint file using the -p option to chkchk, which gives you much of the data in the form of an input file. In addition to the structure, its output also includes the cartesian force constants if present (for Opt=FCCards)
and the MOs (for Guess=Cards). Note that the output may need some editing before using. See the Gaussian 16 User’s Reference for more information about chkchk-p.

Read Checkpoint File Gaussian Tool

Last updated on: 15 August 2016.