;jshsqce
;hsqc employing gradients for coherence selection
;Phase sensitive by sampling +/- coherence in alternate scans. 
;by J. Schleucher, University of Frankfurt 1993
;L. E. Kay et al. JACS 114 (1992), 10663-5
;J. Schleucher et al. Angew. Chem. Int. Ed. Eng. 1993 32(10), 1489
;J. Schleucher et al. J. Biomol. NMR 1994 4, 301
;comments to: js@krypton.org.chemie.uni-frankfurt.de
;BMRB Pulse Sequence Accession Number: 6
#include <Grad.inclk>
  
;  d5 =p3-p1
;  d6 =d5/2
;  d8 =p16+d16+3u
;  d12=p16+d16+p2+6u
  ;d24=d4/2

1 ze
2 d1 
  6m
3 6m
4 30u pl1:f1 pl11:f2
  (p1 ph10):f1
  d4                    ;1/4J
  ;3u
  (p4 ph1):f2 (d5 p2 ph0):f1
  3u
  d4 ;pl13:f2
  ;(p7 ph0):f1
  3u
  (p1 ph1):f1 (p9 ph4):f2
  d0 
  (p2 ph0):f1
  d0 
  GRADIENT(cnst21)
  d16
  (p4 ph0):f2
  d12
  (p3 ph5):f2 (d6 p1 ph0):f1
  d24
  (p4 ph0):f2 (d5 p2 ph0):f1 
  d24
  (p3 ph6):f2 (d6 p1 ph1):f1 
  d4
  (p4 ph1):f2 (d5 p2 ph0):f1
  d4
  (p1 ph0):f1
  d8
  (p2 ph0):f1
  3u
  GRADIENT(cnst22)
  d16 
  20u pl12:f2
  go=2 ph31 cpd2:f2
  d1 do:f2 wr #0 if #0 zd
  3m ip6
  3m ip6
  lo to 3 times 2
  3m id0
  lo to 4 times l2
exit


ph0=0
ph1=1
ph4=0 2
ph5=0 0 2 2  
ph6= 1 1 3 3
ph10=0 0 0 0 2 2 2 2
ph31=0 2 2 0 2 0 0 2

;DS	2*NS!! otherwise, signal cancellation will occur!!
;p16	gradient pulse, e.g. 1 ms
;d16	gradient recovery, e.g. 300 us
;d4:	1/4J H-X
;d24:	1/4J H-X if only X_H moieties are of interest, 1/8J if X-H2 are to be
;	observed
;	Gradient program 2sineea, gradient ratios (cnst21-24, g gyromagnetic
;	ratio):
;	cnst21:gH	cnst22:gX
;	cnst23:-gH	cnst24:gX
;	e.g. for carbon 78, 20, -78, 20: