The duration (A)of S-spin chemical shift evolution during the first t1 increment(Ist two FIDs) dictates the extent of phase correction required in the o dimension. 1H coupled HSQC t红 pwx G △=2×(2pwx/π)+4(0) off-resonance effects 1 st order(lp1)=-360×sw1×△ zero order(rp1)=-phc1/2 1H decoupled HSOC 2xpw 1/4Js t1/2 2 G △=2×(2DwX/π)+2×Dw+t.(0)