Experiment: polyatomic+polyatomic on esol

FOLD 1/5
RMSE: 0.9593, MAE: 0.7000, R2: 0.7531

FOLD 2/5
RMSE: 0.6840, MAE: 0.4976, R2: 0.8612

FOLD 3/5
RMSE: 0.7321, MAE: 0.5618, R2: 0.8531

FOLD 4/5
RMSE: 0.7950, MAE: 0.5903, R2: 0.8246

FOLD 5/5
RMSE: 0.8642, MAE: 0.6658, R2: 0.7967

====== K-FOLD SUMMARY ======
RMSE: 0.8065  [0.7255, 0.8936]
MAE: 0.6036  [0.5347, 0.6644]
R2: 0.8184  [0.7835, 0.8490]

★ Using fold 2 model for test inference
RMSE: 0.7075, MAE: 0.5147, R2: 0.8612

====== HELD-OUT TEST METRICS ======
{'rmse': 0.7074806092102082, 'mae': 0.5146545767784119, 'r2': 0.8611921668052673}
Test RMSE: 0.7043  (95 % CI: 0.5948–0.8139)

Test MAE : 0.5150  (95 % CI: 0.4441–0.5884)

Test R²  : 0.8595  (95 % CI: 0.8011–0.9025)