Author Topic: new $nics keyword  (Read 107 times)

KrisR

  • Jr. Member
  • **
  • Posts: 11
  • Karma: +0/-0
new $nics keyword
« on: October 28, 2022, 10:55:02 AM »
I've seen in the last manual that there is a $nics keyword that should do the whole work of computing NICS (I was using q-atoms before, alas new students = new exercises).

Nucleus-independent chemical shieldings (NICS) can be calculated be setting $nics
in the control file and then listing the Cartesian coordinates in atomic units just as
the coordinates of the molecule itself.


I've created benzene with additional two points:
$coord
    2.05588796505036      1.68402404851466      0.01516391056533  c
    2.48612455534683     -0.93838468765131      0.02418351107795  c
    0.43032714661900     -2.62246111632524      0.00904310664784  c
   -2.05589029227720     -1.68402122622670     -0.01516491195567  c
   -2.48612441178554      0.93838492866293     -0.02419319040299  c
   -0.43033060950763      2.62246059088585     -0.00903276206521  c
    3.66851384517718      3.00485075848661      0.02695380819272  h
    4.43631389897885     -1.67441781569305      0.04314887848871  h
    0.76826755601571     -4.67959868306174      0.01615853533541  h
   -3.66851217933946     -3.00485066044309     -0.02695785779977  h
   -4.43631068360695      1.67441659065383     -0.04319580204844  h
   -0.76826679067109      4.67959727219729     -0.01610722603584  h
$nics
    0. 0. 0.
    0. 0. 1.88973
$end

and submitted it to mpshift.

I can't find anything concerning NICS in the output of mpshift. How to get this $nics command to work?
As students prefer to use TmoleX, also would be nice if somebody could explain how to do it in GUI.

Thanks for help, Kris

uwe

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 520
  • Karma: +0/-0
Re: new $nics keyword
« Reply #1 on: November 04, 2022, 04:31:01 PM »
Hello,

in the output of mpshift, the NICS are printed after the shifts of the nuclei:
Quote
  ***  nmr shielding constants written onto general input/output file!  ***


----------------------------------------------------------------------------
 Nucleus-Independent Chemical Shieldings

NICS        1   ISOTROPIC:        7.9955941       ANISOTROPIC:        5.2238529

  diamagnetic part of magnetic shielding:
    Trace =       9.46296309
    Tensor :
               22.37667965          0.00000000         -0.00000000
                0.00000000         22.35342034          0.00000000
                0.00000000         -0.00000000        -16.34121072

But you will find the results also in the control file at the keyword $nics dft. This usually points to file=nics_dft:
$nics dft    file=nics_dft

and the file nics_dft should contain the results:

$nics dft
# DFT Nucleus-Independent Chemical Shifts ; written at 2022-11-04 16:26:14
# The signs of the computed shielding values are reversed so that the NICS values
# correspond to the familiar NMR chemical shift convention.
# See also: J. Am. Chem. Soc. 1996, 118, 6317.
#   x                   y                   z                   ISOTROPIC     ANISOTROPIC   dD/dB-CONTRIBUTION
    0.00000000000000    0.00000000000000    0.00000000000000    -7.99559414   -5.22385294   20.63399624
    0.00000000000000    0.00000000000000    1.80000000000000   -10.67704606  -26.49677545    2.34206966
$end


If you do not have this file and those results, please check that you have been using Turbomole version 7.6 or newer.

TmoleX does not yet know of NICS, so it is currently not possible to use the graphical user interface for this option (status: November 2022).