Experimental data from the recently discovered iron-based superconductor (IBS) KCa${}_2$Fe${}_4$As${}_4$F${}_2$ is analyzed within a realistic five-band $s_{\pm }$ Eliashberg model with coupling provided by antiferromagnetic spin fluctuations. Fundamental parameters are deduced from available angle resolved photoemission spectoscopy (ARPES) and ab-initio density functional theory (DFT) data, and several physical properties are calculated: critical temperature, upper critical field, gap values, resistivity and superfluid density. This procedure, usually extremely successful in IBSs, highlights the peculiar behavior of this new compound in which $s$ and $d$ -wave character might coexist and where the electron band is close to vanish.

来自最近发现的铁基超导体 (IBS) KCa 的实验数据${}_2$铁${}_4$作为${}_4$F${}_2$ 在现实的五波段内进行分析 ${秒}_{\pm }$反铁磁自旋涨落提供耦合的 Eliashberg 模型。从可用的角度分辨光电发射光谱 (ARPES) 和 ab-initio 密度泛函理论 (DFT) 数据推导出基本参数，并计算几个物理属性：临界温度、上临界场、间隙值、电阻率和超流体密度。这个程序通常在 IBS 中非常成功，突出了这种新化合物的特殊行为，其中$秒$ 和 $d$ -波特征可能共存，电子带接近消失。