采用红外（IR）光谱技术开展了碳酸钙的结构研究。实验发现,碳酸钙的红外吸收模式包括碳酸钙CO₃不对称伸缩振动模式（ν）、碳酸钙 CO₃对称伸缩振动模式（ν）、碳酸钙CO₃面外弯曲振动模式（r）和碳酸钙CO₃面内弯曲振动模式（β）等。采用变温红外（TD-IR）光谱开展了碳酸钙的热稳定性研究。在293~393 K的温度范围内,碳酸钙主要官能团对应的吸收强度及频率都有一定的改变。采用二维红外（2D-IR）光谱进一步研究了碳酸钙ν、r和β吸收峰变化快慢的信息,证明了三级红外（IR）光谱在重要的无机盐（碳酸钙）结构及热稳定性研究中的重要作用。

The calcium carbonate structure was studied by infrared（IR） spectroscopy.There were calcium carbonate CO₃asymmetrical stretch vibrationmode（ν）,calcium carbonate CO₃ symmetrical stretching vibration mode（ν）,calcium carbonate CO₃ out-of-plane bending vibration mode（r） and calcium carbonate CO₃ in-plane bending vibration mode（β）.Temperature-dependent infrared（TD-IR） spectroscopy was also used to study the thermal stability of calci-um carbonate.In the temperature range of 293~393 K,the infrared absorption intensity and frequency of the main functional groups of calcium carbonate had some changes.Two-dimensional infrared（2D-IR） spectroscopy of the calcium carbonate（ν,r and β） were studied to the frequency information of the absorption peak change.The key roles of third-step IR spectroscopy in the analysis of structure and thermal stability of the important inorganic salt（calcium carbonate） were demonstrated.