z-filter ±3QMAS pulse program for spins 3/2, 5/2, and 7/2
Contributor: Y. Millot

Below NMR pulse program describes the z-filter ±3QMAS (1D and 2D) experiment with cogwheel phase cycling or nested phase cycling applied to nuclei with 3/2, 5/2, or 7/2 spins.

Fig. 1: Z-filter ±3QMAS NMR pulse sequence and coherence transfer pathway.
The echo amplitude and the antiecho amplitude have the same sign.

This NMR pulse program is for Bruker Avance spectrometers.

A pure absorption 2D spectrum is obtained with the shearing transformation.

Code for Avance NMR spectrometers

; 3qzfilter.ym (XWIN-NMR 3.0)
; 01072009

;±3Q MAS pulse program for half integer spin nuclei
;ZGOPTNS (zg-options) are:
;  -DTQS3Cog ... for I=3/2 (ns=24) Cog24(0,4,19,7)  = Cog24(23,3,18,6)
;  -DTQS3Nes ... for I=3/2 (ns=24) nested phase cycling with standard receiver
;  -DTQS5Cog ... for I=5/2 (ns=36) Cog36(0,6,29,11) = Cog36(34,4,27,9)
;  -DTQS5Nes ... for I=5/2 (ns=36) nested phase cycling with standard receiver
;  -DTQS7Cog ... for I=7/2 (ns=48) Cog48(0,8,25,1)  = Cog48(11,19,36,12)
;  -DTQS7Nesdig .for I=7/2 (ns=48) nested phase cycling with digital receiver

;d1 : recycle delay
;p1 : excitation pulse at pl11
;p2 : conversion pulse at pl11
;p3 : 90 degree selective pulse at pl13
;pl1 : =120 dB
;pl11 : power level for excitation and conversion pulses
;pl13 : power level for selective pulse
;d4 : =20u, delay for z-filter 
;d0 : =3u
;in0 : 1 rotation period for synchronised experiment
;td1 : number of t1-experiments
;FnMODE : States or TPPI
;Shearing use AU program xfshear (FnMode = States) 
;ph31 ph30:r for receiver phase <> kpi/2

  ze                  ; clear memory, new data replace old data,
                      ; switch AD converter to replace mode,
                      ; perform DS before next acquisition,

1 d1                  ; recycle delay,
  10u pl11:f1         ; 10 microsecond delay,
                      ; set high power in f1 channel,
  (p1 ph1):f1         ; high-power excitation pulse,
  d0                  ; delay between pulses, t1 increment,
  (p2 ph2):f1         ; high-power conversion pulse,
  d4  pl13:f1         ; set low power in f1 channel,
  (p3 ph3):f1         ; low-power 90° pulse,
#ifdef TQS7Nesdig
  go=1 ph31 ph30:r    ; instruction must be in that order
                      ; signal acquisition,
                      ; loop to 1, ns times for averaging,
#else
  go=1 ph31           ; signal acquisition,
                      ; loop to 1, ns times for averaging,
#endif
  d1 mc #0 to 1 F1PH(ip1, id0)
                      ; delay for disk I/O, store signal,
                      ; increase FID number,
                      ; delete memory data,
                      ; increment p1 pulse phase by 360°/12 
                      ; for States procedure,
                      ; increment time d0 by in0,
  exit                ; end of the pulse program

#ifdef TQS3Cog 
 ph10= (24) 0  1  2  3  4  5  6  7  8  9 
           10 11 12 13 14 15 16 17 18 19 
           20 21 22 23
 ph1 = (12) ph10*23   ; excitation pulse phase
 ph2 =      ph10*3    ; conversion pulse phase
 ph3 =      ph10*18   ; 90° selective pulse phase
 ph31=      ph10*6    ; receiver phase :(360/24)*6*m=90*m
#else
#ifdef TQS3Nes 
 ph1 = (12) 0 2 4 6 8 10
 ph2 =      0
 ph3 =     {0}*6 {1}*6 {2}*6 {3}*6
 ph31=      ph1*3 + ph3
#else 
#ifdef TQS5Cog 
 ph10= (36) 0  1  2  3  4  5  6  7  8  9 
           10 11 12 13 14 15 16 17 18 19 
           20 21 22 23 24 25 26 27 28 29 
           30 31 32 33 34 35
 ph1 = (12) ph10*34   ; excitation pulse phase
 ph2 =      ph10*4    ; conversion pulse phase
 ph3 =      ph10*27   ; 90° selective pulse phase
 ph31=      ph10*9    ; receiver phase :(360/36)*9*m=90*m
#else
#ifdef TQS5Nes 
 ph1 = (12) 0 2 4 6 8 10
 ph2 = (6) {0}*6 {1}*6 {2}*6 {3}*6 {4}*6 {5}*6
 ph3 =      0
 ph31=      ph1*3 - ph2*3
#else 
#ifdef TQS7Cog 
 ph10= (48) 0  1  2  3  4  5  6  7  8  9 
           10 11 12 13 14 15 16 17 18 19 
           20 21 22 23 24 25 26 27 28 29 
           30 31 32 33 34 35 36 37 38 39 
           40 41 42 43 44 45 46 47
 ph1 = (12) ph10*11   ; excitation pulse phase
 ph2 =      ph10*19   ; conversion pulse phase
 ph3 =      ph10*36   ; 90° selective pulse phase
 ph31=      ph10*12   ; receiver phase :(360/48)*12*m=90*m
#else
#ifdef TQS7Nesdig 
 ph1 = (12) 0 2 4 6 8 10
 ph2 =      0
 ph3 = (8) {0}*6 {1}*6 {2}*6 {3}*6 {4}*6 {5}*6 {6}*6 {7}*6
 ph30=      ph1*3 + ph3
 ph31=      0
#endif
#endif
#endif
#endif
#endif
#endif
  

This pulse program remains valid for the third pulse with strong amplitude for better excitation of off-resonance nuclei.