Calculating Q6 for nuclei in Vapor

[Nomula Raghavendra]

Hello,

I want to calculate Q6 of the atoms that formed nuclei from vapor. Since I don't know about the atom ids as this is an random event I want to try the script I mentioned below. Is it correct:

#  Compute Coordination Number (Find Crystalline Atoms)
cn: COORDINATIONNUMBER SPECIES=1-2000 R_0=1.5 MORE_THAN={RATIONAL R_0=6.0 NN=6 MM=12 D_0=0} LOWMEM

# Build Contact Matrix for Clustering
cm: CONTACT_MATRIX ATOMS=cn SWITCH={CUBIC D_0=1.45 D_MAX=1.55}

# Identify Largest Nucleus Using Depth First Search Clustering
dfs: DFSCLUSTERING MATRIX=cm LOWMEM

# Get Size of the Largest Cluster
clust_size: CLUSTER_NATOMS CLUSTERS=dfs CLUSTER=1 LOWMEM

# Extract Atom IDs of Largest Cluster
atomid: OUTPUT_CLUSTER CLUSTERS=dfs CLUSTER=1 STRIDE=1000

# Compute Q6 ONLY for Atoms in the Largest Cluster
q6: Q6 SPECIES=atomid SWITCH={GAUSSIAN D_0=1.38 R_0=0.1 D_MAX=1.4} MEAN LOWMEM

# Compute Local Averaged Q6 (aq6) for Nucleus Atoms
aq6: LOCAL_AVERAGE SPECIES=atomid SWITCH={GAUSSIAN D_0=1.38 R_0=0.1 D_MAX=1.4} MEAN MORE_THAN1={SMAP R_0=0.25 D_0=0.0 A=8 B=8} LOWMEM

# Print Results
PRINT ARG=cn.*,clust_size.*,q6.*,aq6.* STRIDE=1000 FILE=colvar.out FMT=%15.6f

Can anyone help me with this please? I want to do this to define final basin for my Committor analysis. I had tried to calculate the values of average q6 only for the vapor system how the values are largely fluctuating and never converging, does this mean q6/average q6 is not a good order parameter to differentiate between a crytalline cluster and vapor? Please share your thoughts.

Thanks and Regards
Raghu