CCP4 Roadmaps
	DENSITY IMPROVEMENT

DENSITY MODIFICATION AND MOLECULAR AVERAGING

There are three different programs for density improvement. 'dm' reads reflection data file with associated phases; SOLOMON reads a map. Both generate an improved map/phases. 'dmmulti' is only used when there are reflection data from multiple crystal forms, and some initial phases are available.

Auxiliary CCP4 programs used in these tasks

DM_NCS_AVERAGING

'dm' for NCS averaging (see 'dm')

DM_SKELETONISATION

Iterative skeletonisation using 'dm' (see 'dm')

MAPROT

Map skewing, interpolating, rotating, averaging and correlation masking

MATTHEWS_COEF

Cell content analysis (Matthews Coefficient and solvent content)

MLPHARE

Maximum likelihood heavy atom refinement and phase calculation

NCSMASK

Manipulate the averaging mask

NCSREF

NCS phased refinement; refining molecular replacement solutions when the structure contains NCS models

SFALL

Structure factor calculation and X-ray refinement using forward and reverse FFT

SIGMAA

Improve Fourier coefficients using calculated phases

Further reading

'dm' Workshop

CCP4i Documentation on Density Improvement

CCP4 Program Documentation