Dear charmm users,
Can anyone please help me with good angle parameter for angle C11-C12-C15 (CG321 C301 CG321) of my doxorubicin molecule attached?

I have obtained the following approximate matches.
Approximate matches:
CG2DC2 CG301 CG321 32.00 112.20 ! RETINOL MECH
CG2DC2 CG301 CG331 32.00 112.20 ! RETINOL MECH
CG2O3 CG301 CG331 52.00 108.00 ! AMOL, alpha-methoxy-lactic acid, og
CG2O3 CG301 OG301 45.00 109.00 ! AMOL, alpha-methoxy-lactic acid, og
CG2O3 CG301 OG311 75.70 110.10 ! AMOL, alpha-methoxy-lactic acid, og
CG311 CG301 CG311 58.35 113.50 11.16 2.561 ! CA, CHOLIC ACID, chayan, 03/06
CG311 CG301 CG321 58.35 113.50 11.16 2.561 ! CA, CHOLIC ACID, chayan, 03/06
CG311 CG301 CG331 58.35 113.50 11.16 2.561 ! CA, CHOLIC ACID, chayan, 03/06
CG321 CG301 CG331 58.35 113.50 11.16 2.561 ! RETINOL TMCH/MECH
CG331 CG301 CG331 58.35 113.50 11.16 2.561 ! RETINOL TMCH/MECH
CG331 CG301 OG301 45.00 111.50 ! AMOL, alpha-methoxy-lactic acid, og
CG331 CG301 OG302 75.70 110.10 ! AMGT, Alpha Methyl Gamma Tert Butyl Glu Acid CDCA Amide, chayan
CG331 CG301 OG311 75.70 110.10 ! AMOL, alpha-methoxy-lactic acid, og
CG331 CG301 CLGA3 97.00 111.20 ! TCLE
CG331 CG301 BRGA3 98.00 111.20 ! TBRE
OG301 CG301 OG311 45.00 116.50 ! AMOL, alpha-methoxy-lactic acid, og
CLGA3 CG301 CLGA3 95.00 109.00 ! TCLE
BRGA3 CG301 BRGA3 90.00 110.50 ! TBRE

Thanking you