Central-line intensity optimization with a two-pulse sequence in solid-state MAS NMR using a JDK1.3 applet

Home and Applets > JDK1.3 Java Applet for Two Pulses > Simpson 2

We have simulated the same experiment as that described in Example 2 using SIMPSON version 1.1.0, a general simulation program for solid-state NMR spectroscopy provided by M. Bak, J. T. Rasmussen, and N. C. Nielsen, J. Magn. Reson. 147, 296-330 (2000).

*****Simpson 2 for two pulses*****

# twop2.in
# spin-3/2 central-line intensity optimization
# with p2 in two-pulse MAS sequence

spinsys {
  channels 23Na
  nuclei   23Na
  quadrupole 1 1 1e6 0 0 0 0
}



par {
  spin_rate        10000
  variable tsw     0.25
  sw               1.0e6/tsw
  np               41
  crystal_file     rep320
  gamma_angles     10
  start_operator   I1z
  verbose          1101
  variable rf      100000
  proton_frequency 400e6
}

proc pulseq {} {
  global par
  maxdt $par(tsw)

  matrix set 1 elements {{1 4} {4 1}}




  matrix set detect elements {{2 3}}



  acq

  pulse 6 $par(rf) x


  filter 1


  for {set i 1} {$i < $par(np)} {incr i} {

    pulse $par(tsw) $par(rf) x


    acq -y

  }
}

proc main {} {
  global par

  fsave [fsimpson] $par(name).fid
  puts "Larmor frequency (Hz) of 23Na: "
  puts [resfreq 23Na $par(proton_frequency)]
}

****Comment****

File name.
Description.




Spin I = 3/2.
1st-order
quadrupole
interaction,
qcc = 1 MHz,
eta = 0.

10 kHz.
0.25 µs increment.

2nd pulse: 10 µs.




100 kHz RF pulse.





0.25 µs increment.

3Q and -3Q from
the 1st pulse,
density matrix
convention

Central transition,
fictitious spin-1/2
convention.

No pulse,
no signal.
The 1st x-pulse
has 6 µs duration.

Select -3Q and 3Q
coherences.



2nd x-pulse is
variable pulse.

Receiver -y.

SIMPSON uses gyromagnetic ratios provided by IUPAC for the determination of the Larmor frequency of a nucleus. For example:

23Na Larmor frequency = Proton Larmor frequency * 23Na gyromagnetic ratio / Proton gyromagnetic ratio;

400 MHz * 7.0808493 / 26.7522128 = 105.8731007 MHz.


This curve represents the simulated central-line intensity versus the second-pulse length p2 with SIMPSON for a spin I = 3/2 system excited by the two-pulse MAS sequence.

Central-line intensity versus p2 simulated with SIMPSON

Correlation curve of SIMPSON versus JDK1.3 Java applet for the two-pulse MAS sequence

This figure represents the correlation curve relating two simulations generated with SIMPSON (Simpson 2) and JDK1.3 Java applet (Example 2) for the two-pulse MAS sequence applied to a spin I = 3/2 system.

Solid-state NMR bibliography for:

Aluminum-27
Antimony-121/123
Arsenic-75
Barium-135/137
Beryllium-9
Bismuth-209
Boron-11
Bromine-79/81
Calcium-43
Cesium-133
Chlorine-35/37
Chromium-53
Cobalt-59
Copper-63/65
Deuterium-2
Gallium-69/71
Germanium-73
Gold-197
Hafnium-177/179
Indium-113/115
Iodine-127
Iridium-191/193
Krypton-83
Lanthanum-139
Lithium-7
Magnesium-25
Manganese-55
Mercury-201
Molybdenum-95/97
Neon-21
Nickel-61
Niobium-93
Nitrogen-14
Osmium-189
Oxygen-17
Palladium-105
Potassium-39/41
Rhenium-185/187
Rubidium-85/87
Ruthenium-99/101
Scandium-45
Sodium-23
Strontium-87
Sulfur-33
Tantalum-181
Titanium-47/49
Vanadium-51
Xenon-131
Zinc-67
Zirconium-91
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