I'm not certain why you don't want to split the chains, but it is possible to get Chimera to compute the per-chain surfaces without splitting the model. The simplest way is to use the Multiscale Models tool (in the Higher-Order Structure category). With that dialog up, click its "Make models" button. Then in the "Select chains" section at the top, click the "All" button. Then in the "Resolution" entry field near the center of the dialog type "0" (zero) and then click the "Resurface" button near that field. You will get some complaints about multiple-component surfaces failing, but since all the single-component surfaces work the entire structure will be surfaced.

On Nov 29, 2012, at 3:00 AM, Anton Vila Sanjurjo wrote:

Hi,

I have seen posts regarding this problem before. Here is the log I got after attempting to render a surface representation of the 50S ribosomal subunit (rcsb ID: 3CPW).

#0, chain 0: 23S ribosomal rna
#0, chain 1: L35E
#0, chain 2: 50S ribosomal protein L44E
#0, chain 4: 5'-R(*cp*cp*ap*(phe)*(aca))-3'
#0, chain 9: 5S ribosomal rna
#0, chain A: 50S ribosomal protein L2P
#0, chain B: 50S ribosomal protein L3P
#0, chain C: 50S ribosomal protein L4P
#0, chain D: 50S ribosomal protein L5P
#0, chain E: 50S ribosomal protein L6P
#0, chain F: 50S ribosomal protein L7AE
#0, chain G: HS6
#0, chain H: 50S ribosomal protein L10E
#0, chain I: 50S ribosomal protein L13P
#0, chain J: HMAL13
#0, chain K: 50S ribosomal protein L15P
#0, chain L: 50S ribosomal protein L15E
#0, chain M: 50S ribosomal protein LC12
#0, chain N: 50S ribosomal protein L18E
#0, chain O: 50S ribosomal protein L19E
#0, chain P: 50S ribosomal protein L21E
#0, chain Q: HL31
#0, chain R: 50S ribosomal protein L23P
#0, chain S: 50S ribosomal protein L24P
#0, chain T: 50S ribosomal protein L24E
#0, chain U: HL21/HL22
#0, chain V: 50S ribosomal protein L30P
#0, chain W: 50S ribosomal protein L31E
#0, chain X: 50S ribosomal protein L32E
#0, chain Y: HL5
#0, chain Z: 50S ribosomal protein L37E
C:\Program Files\Chimera 1.7s\bin\mscalc.exe 1.400000 2.000000 1
MSMSLIB 1.3 started on Local PC
Copyright M.F. Sanner (March 2000)
Compilation flags
C:\Program Files\Chimera 1.7s\bin\mscalc.exe 1.400000 2.000000 0
MSMSLIB 1.3 started on Local PC
Copyright M.F. Sanner (March 2000)
Compilation flags
Surface calculation failed, mscalc returned code 5.

Surface calculation frequently fails for large, multi-chain structures. The calculation may be successful if the chains are treated individually, by using the "split" command before generating a surface. If splitting is not desired or the structure is already a single chain, changing molecular surface parameters in the Selection Inspector or (before surface creation) the New Surfaces category of Preferences may allow the calculation to succeed.

C:\Program Files\Chimera 1.7s\bin\mscalc.exe 1.400000 2.000000 1
MSMSLIB 1.3 started on Local PC
Copyright M.F. Sanner (March 2000)
Compilation flags

Surface 3CPW.pdb, category ligand, probe radius 1.4, vertex density 2
1 connected surface components
Total solvent excluded surface area = 989.35
Total solvent accessible surface area = 1473.85

In this case, I am not interested in splitting the file into its individual chains. I have also unsuccessfully played with the probe-radius and vertex parameters. I should mention that I was able to get this to work with previous versions of Chimera (1.5.something) and that small proteins can be successfully rendered with the latest versions.

best,

Antón