Hi,

Here is this simple dialkyne calculation I am trying out. But it keeps throwing back an Optimization failed error. I have tried to delete either triple bond and the calculation goes. I have included the input script and the error message. Please help and many thanks!

input:

```
molecule dialkyne {
0 1
C -0.227988 1.061533 -0.439807
C -0.813436 -0.019416 0.219199
C 0.011463 -1.218532 0.569446
C 1.444186 -1.004997 0.099087
C 2.254207 -2.182485 0.443017
C 2.922061 -3.153312 0.726584
C 1.046636 1.027292 -0.753065
C 2.223211 0.995684 -1.042227
C -2.167564 0.016946 0.551865
C -2.936101 1.134272 0.225621
C -0.996524 2.178859 -0.766051
C -2.350649 2.215248 -0.433288
H 0.001741 -1.365476 1.672660
H -0.412330 -2.118720 0.070618
H 1.453907 -0.858053 -1.004128
H 1.867979 -0.104809 0.597914
H 3.522689 -4.026415 0.981607
H 3.281353 0.967258 -1.302282
H -2.629344 -0.835545 1.071498
H -4.003967 1.162924 0.487996
H -0.534768 3.031322 -1.285751
H -2.956761 3.096420 -0.690512
}
set basis sto-3g
optimize('scf')
```

error message:

TORS::compute_val: unable to compute torsion value

Optimizer: Optimization failed!

output:

`Performing BFGS update. Previous computed or guess Hessian on step 1. Change in internal coordinate of 6.20e-01 exceeds limit of 5.00e-01. Skipping Hessian update for step 3. Change in internal coordinate of 7.46e-01 exceeds limit of 5.00e-01. Skipping Hessian update for step 2. Change in internal coordinate of 8.63e-01 exceeds limit of 5.00e-01. Skipping Hessian update for step 1. Steps to be used in Hessian update: 4 Taking RFO optimization step. Going to follow RFO solution 1. Using RFO vector 1. Norm of target step-size 0.96136 Projected energy change by RFO approximation: -0.0128049595 Back-transformation to cartesian coordinates... The INTCO_EXCEPTion handler: TORS::compute_val: unable to compute torsion value Dynamic level is 0. exc.g_really_quit() is 0. **** Optimization has failed! (in 5 steps) **** -------------------------- OPTKING Finished Execution -------------------------- Cleaning optimization helper files. *** Psi4 exiting successfully. Buy a developer a beer!`