thanks..

For your ref.. I have attached two 1D spectra to show the offset error. I have used off resonance sinc pulse (CO 180 of CA) on 62spins(13C).
Pulse sequence= shaped_pulse + step(spin_system,Ly_C,rho,pi/2)-->acquire;
Case1:
inter.zeeman.scalar=num2cell(linspace(0,180,62));
parameters.offset=35 %(in ppm)
result: wrong_offset.eps (attached)
Case2:
inter.zeeman.scalar=num2cell(linspace(-35,145,62)); %[(0-35),(180-35)]
parameters.offset=0 %(in ppm)
result: offset_corrected.eps (attached)
of course..it is not in good CO range..but this offset error can play a big role in 2D exps!