MQMAS shearing with RMN(fat):
Contribution of Y. Millot




Home and Applets > Pulse Program > XwinNMR 2.6, ASX, MSL > MQMAS Data Processing: Anti-Echo File

5 - Anti-echo file

For aluminum-27 (I = 5/2), which has a positive gyromagnetic ratio, and for 3QMAS experiment performed with the two-pulse program, the antiecho fanti-echo(t1, t2) signal is related to the cosine Scos(t1, t2) and sine Ssin(t1, t2) signals by:

fanti-echo(t1, t2) = Scos(t1, t2) - i*Ssin(t1, t2)   .

To get -i*Ssin(t1, t2) from i*Ssin(t1, t2) obtained previously for the echo signal, we apply a phase shift of 180 to i*Ssin(t1, t2).

(1) To this end, we recall the sin files by selecting the menu items:

Data/sin

(2) We perform twice a 90-phase correction, that is, we select twice the menu items:

Process/Phase/Phase Correct

We obtain exp(i*Pi/2)*exp(i*Pi/2)*i*Ssin(t1, t2), that is, -i*Ssin(t1, t2).

Intensity plot of the -i-phase corrected sine file of 2D MQMAS data

Figure 1 Intensity plot of the -i-phase corrected sine file of 2D MQMAS data:
Both axes of the 2D map are labeled in time units.



(3) We add the Scos(t1, t2) file with -i*Ssin(t1, t2) file to build the anti-echo file fanti-echo(t1, t2) by selecting the menu items:

Data/Add Data...

Add files panel

A window appears, in which we add sin to cos. (The two shadowed rectangles are in fact pop-up lists of filenames, clicking on them allows us to choose files.) We save the resulting file with antiecho filename.



Three 2D files corresponding to the 2D anti-echo MQMAS data appear on the desktop:

  • antiecho -> 2D Data - Stacked Plot
  • antiecho -> 2D Data - Line Contour Plot
  • antiecho -> 2D Data - Intensity Plot
Intensity plot of the anti-echo signal of 2D MQMAS data

Figure 2 Intensity plot of the 2D anti-echo MQMAS data:
Both axes of the 2D map are labeled in time units.


 

(top)

[Contact me] - Last updated December 16, 2012
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



Copyright 2002- pascal-man.com. All rights reserved.