The choice of accessories depends on the sample state. For solids and liquids, an ATR (Attenuated Total Reflectance) accessory with a Diamond or ZnSe crystal is highly recommended as it requires minimal sample preparation. For gas analysis, a long-path gas cell is necessary. If you are conducting high-throughput testing, look for autosampler compatibility. Always confirm if the software package includes comprehensive spectral libraries (e.g., polymers, organics, forensics) for easy identification.