Thank you for the kind reply. I realised that, and am now running two jobs, one with conv=4 and the other with conv=5. If this does not work, would it make sense to completely get rid of the SOS and just try to see if CC2 without SOS works?
Here is my new control file:
$title
$operating system unix
$symmetry c1
$redundant file=coord
$user-defined bonds file=coord
$coord file=coord
$optimize
internal on
redundant on
cartesian off
global off
basis off
$atoms
c 1-4,7,9-11,13,15-17,19-21,24-40 \
basis =c aug-cc-pVDZ \
cbas =c aug-cc-pVDZ
n 5-6,8,12,14,18,22-23 \
basis =n aug-cc-pVDZ \
cbas =n aug-cc-pVDZ
h 41-58 \
basis =h aug-cc-pVDZ \
cbas =h aug-cc-pVDZ
$basis file=basis
$rundimensions
dim(fock,dens)=677371
natoms=58
nshell=450
nbf(CAO)=1162
dim(trafo[SAO<-->AO/CAO])=1322
rhfshells=1
nbf(AO)=1082
$scfmo file=mos
$closed shells
a 1-133 ( 2 )
$scfiterlimit 130
$scfconv 7
$thize 0.10000000E-04
$thime 5
$scfdamp start=0.300 step=0.050 min=0.100
$scfdump
$scfintunit
unit=30 size=0 file=twoint
$scfdiis
$maxcor 5000 MiB per_core
$scforbitalshift automatic=.1
$drvopt
cartesian on
basis off
global off
hessian on
dipole on
nuclear polarizability
$interconversion off
qconv=1.d-7
maxiter=25
$coordinateupdate
dqmax=0.3
interpolate on
statistics 5
$forceupdate
ahlrichs numgeo=0 mingeo=3 maxgeo=4 modus=<g|dq> dynamic fail=0.3
threig=0.005 reseig=0.005 thrbig=3.0 scale=1.00 damping=0.0
$forceinit on
diag=default
$energy file=energy
$grad file=gradient
$forceapprox file=forceapprox
$denconv 0.10000000E-06
$cbas file=auxbasis
$ricc2
hard_restart
cc2
geoopt model=cc2 state=(s1)
sos cos= 1.30000
$response
fop unrelaxed_only operators=diplen
sop operators=(diplen,diplen)
$excitations
irrep=a nexc=5
$laplace
conv=5
$last step ricc2
$last SCF energy change = 0.87090939E-08
$charge from dscf
0.000 (not to be modified here)
$dipole from dscf
x -0.00034122219716 y 0.00013060160870 z -0.00003075498512 a.u.
| dipole | = 0.0009319488 debye
$orbital_max_rnorm 0.12832582988654E-03
$excitation_energies_CCS_____1^a___ file=exstates
$excitation_energies_CC2_____1^a___ file=exstates
$t2_norm_of_re0_CC2_____1^a___ file=exstates
$t2_norm_of_le0_CC2_____1^a___ file=exstates
$<le0|re0>-overlap_CC2_____1^a___ file=exstates
$<le01|re01>-overlap_CC2_____1^a___ file=exstates
$<le02|re02>-overlap_CC2_____1^a___ file=exstates
$end