Hi all,

I tried to simulate a D-F REDOR-type curve between a single deuteron
and a single fluorine atom. To better refocus the quadrupolar
interaction, I used a single 90 pulse (properly phased) on the
deuterium channel, and a series of pulses on the fluorine channel to
reintroduce the dipolar coupling between the two. Here's my question-
- if I set the dipolar coupling to 0.0, and run the same pulse
program, the signal still dephases. If the deuteron and fluorine
aren't dipolar coupled, I wouldn't expect this to happen. Can
someone give me a hand with this? My code follows-- hopefully I
haven't made some stupid error-- I don't think I have...

A few more details-- if I turn off the pulses on the F-channel-- the
signal doesn't dephase, as you would expect. If there are pulses on
the F-channel, I see dephasing. If the dipolar coupling is turned
on/turned up, the signal dephases faster, as you'd expect.

Thanks,
Mike

spinsys {
channels 2H 19F
nuclei 2H 19F
dipole 1 2 -0 0 0 0
quadrupole 1 1 60000 0 10 200 45
#shift 2 0 40p 0.5 0 90 0

}


par {
method direct
proton_frequency 500.217e6
spin_rate 5000
gamma_angles 10
sw spin_rate/8.0
np 200
crystal_file rep320
start_operator I1x
detect_operator I1p
#verbose 1111111111
variable rf 100000
variable rf2 40000
#variable dipole -40.872
variable dipole 50
#various 0100


}

proc pulseq {} {
global par
maxdt 1.0
set np2 [expr $par(np)-1]
set t180 [expr 0.5e6/$par(rf)]
set tc180 [expr 0.5e6/$par(rf2)]
set tc90 [expr $tc180/2]
set tr2 [expr 0.5e6/$par(spin_rate)-$t180]
set tr3 [expr 0.5e6/$par(spin_rate)-$tc90-$t180]


reset

pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr3
pulse $tc180 $par(rf2) y 0 x
delay $tr3
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
store 1

reset
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
store 2
store 4

reset
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
pulse $t180 0 x $par(rf) y
delay $tr2
pulse $t180 0 x $par(rf) x
delay $tr2
store 3
store 5

reset


prop 1
acq

reset

prop 3
prop 1
prop 2

acq

for {set i 2} {$i < $np2} {incr i} {
reset

prop 4
prop 2
store 2
reset
prop 5
prop 3
store 3
reset

prop 3
prop 1
prop 2
acq
}
}

proc main {} {
global par

set f [fsimpson]
fsave $f HD_redor_QCC60K_ps40K_sspeed5k_dip$par(dipole)
Hz_comp.fid

funload $f
}